Christianity is an Abrahamic monotheistic religion based on the Bible and the teachings of Jesus. The Gospels state that Jesus is the Son of God and rose from the dead after his crucifixion, whose coming as the messiah (Christ) was prophesied in the Old Testament and chronicled in the New Testament. It is the world's largest and most widespread religion with over 2.3 billion followers, comprising around 28.8% of the world population. Its adherents, known as Christians, are estimated to make up a majority of the population in 120 countries and territories.
Christianity remains culturally diverse in its Western and Eastern branches, and doctrinally diverse concerning justification and the nature of salvation, ecclesiology, ordination, and Christology. Most Christian denominations, however, generally hold in common the belief that Jesus is God the Son—the Logos incarnated—who ministered, suffered, and died on a cross, but rose from the dead for the salvation of humankind; this message is called the gospel, meaning the "good news". The four canonical gospels of Matthew, Mark, Luke and John describe the life of Jesus and teachings as preserved in the early Christian tradition, with the Old Testament as the gospels' respected background.
Christianity began in the 1st century, after the death of Jesus, as a Judaic sect with Hellenistic influence in the Roman province of Judaea. The disciples of Jesus spread their faith around the Eastern Mediterranean area, despite significant persecution. The inclusion of Gentiles led Christianity to slowly separate from Judaism in the 2nd century. Emperor Constantine I decriminalized Christianity in the Roman Empire in 313 with the Edict of Milan. In 325, Constantine convened the Council of Nicaea, where the Nicene Creed was adopted, and where Early Christianity was consolidated into what would become the state religion by around 380. The Church of the East and Oriental Orthodoxy both split over differences in Christology during the 5th century, while the Eastern Orthodox Church and the Catholic Church separated in the East–West Schism in 1054. Protestantism split into numerous denominations from the Catholic Church during the Reformation era (16th century). Following the Age of Discovery (15th–17th century), Christianity expanded globally via missionary work, evangelism, immigration, and trade. Christianity played a prominent role in the development of Western civilization, particularly in Europe from late antiquity and the Middle Ages.
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The three main branches of Christianity are Catholicism (1.3 billion people), Protestantism (800 million), and Eastern Orthodoxy (300 million), while other prominent branches include Oriental Orthodoxy (60 million) and Restorationism (35 million). Smaller church communities number in the thousands. In Christianity, efforts toward unity (ecumenism) are underway. In the West, Christianity remains the dominant religion even with a decline in adherence, with about 70% of that population identifying as Christian. Christianity is growing in Africa and Asia, the world's most populous continents. Many Christians are still persecuted in some regions of the world, particularly where they are a minority, such as in the Middle East, North Africa, East Asia, and South Asia.
Etymology
Early Jewish Christians referred to themselves as being of 'The Way' (Koine Greek: τῆς ὁδοῦ, romanized: tês hodoû), an expression possibly coming from Isaiah 40:3, "prepare the way of the Lord". According to Acts 11:26, the term "Christian" (Χρῑστῐᾱνός, Khrīstiānós), meaning "followers of Christ" and referring to Jesus' disciples, was first used in the city of Antioch by the non-Jewish inhabitants there. The earliest recorded use of the term "Christianity/Christianism" (Χρῑστῐᾱνισμός, Khrīstiānismós) was by Ignatius of Antioch around 100 AD. The name Jesus comes from Ancient Greek: Ἰησοῦς (Iēsous), probably from Hebrew/Aramaic: יֵשׁוּעַ (Yēšūaʿ).
History
Early Christianity
Apostolic Age
Christianity originated as a Jewish movement in Judaea during the 1st century AD, within the context of late Second Temple Judaism. The earliest followers of Jesus were Jews who understood his life, death and expected return through familiar Jewish apocalyptic and messianic frameworks. They remained embedded in Jewish religious life and did not initially conceive of themselves as departing from Israel or founding a new faith. Following their conviction that Jesus had been raised from the dead, they established a community in Jerusalem that awaited Jesus’s return and eschatological renewal, seeking to spread this message throughout Israel and the Jewish diaspora. Early Jewish Christianity maintained a high Christology alongside monotheism. This early community was led by the three Pillars of the Church, namely James the Just, Peter, and John. What eventually became of this earliest Christ-following community remains unclear; they were possibly displaced, relocated, or killed when the Romans destroyed Jerusalem in 70 AD.
Meanwhile, as the message about Jesus spread beyond Judea and Galilee into the broader Greco-Roman world, it increasingly attracted Gentile adherents, especially among "God-fearers": non-Jews who were attracted to Judaism and participated in synagogal worship without fully converting. This created a challenge for the movement's Jewish religious outlook, which insisted on close observance of the Jewish commandments. Against this backdrop, Paul the Apostle, a Jew of the Pharisaic school who had initially persecuted the Jesus movement, became one of its most influential missionaries following his conversion, focusing on spreading the message to non-Jews in the Eastern Mediterranean. Paul argued that Gentiles could participate in the promises of Israel through exclusive devotion to the God of Israel, faith in Christ, baptism, and participation in his death and resurrection, without full adherence to the Torah, including circumcision. This had a formative effect on the emerging Christian identity as separate from Judaism. Over time, such developments contributed to the gradual differentiation between the Jesus movement and other Jewish communities, a process that resulted in the emergence of Christianity as a separate religion.
Ante-Nicene period
This formative period was followed by the early bishops, whom Christians consider the successors of Christ's apostles. From the year 150, Christian teachers began to produce theological and apologetic works aimed at defending the faith. These authors are known as the Church Fathers, and the study of them is called patristics. Notable early Fathers include Ignatius of Antioch, Polycarp, Justin Martyr, Irenaeus, Tertullian, Clement of Alexandria and Origen.
During this period, there was no unified Christian movement but rather multiple competing sects, which held radically different beliefs. Christian authors began using the Greek term hairesis, meaning "school of thought", to describe rival communities, which gave rise to the concept of heresy. In the second and third centuries, figures like Justin Martyr, Irenaeus, Tertullian, and Clement of Alexandria, often retrospectively referred to as "proto-orthodox", insisting that there was one original apostolic teaching and that all rivals had deviated from it. Meanwhile, Valentinus, an Alexandrian teacher, developed a Gnostic theology in which Christ brought saving knowledge (gnosis) that enabled believers to be redeemed from the material world. Marcion, from Sinope, drew a distinction between high, purely good god, father of Christ, and the lower, merely "just" god of Israel, who demanded sacrifice and procreation. Marcion is also known to have assembled a collection of Christian texts, including his own gospel, and in doing so created one of the earliest known Christian scriptural canons. Justin Martyr, from Neapolis, disagreed with both, arguing the God of the Jewish scriptures was Christ himself before his incarnation. A gradual splitting off of Gentile Christianity left Jewish Christians continuing to follow the Law of Moses, including practices such as circumcision. By the fifth century, they and the Jewish–Christian gospels would be largely suppressed by the dominant sects in both Judaism and Christianity.
Christianity occupied an unstable position within the Roman world. In antiquity, what moderns call "religion" was closely associated with ancestral traditions and embedded within other aspects of ethnic identity. It is possible that Gentile Christians, having rejected their native gods, were perceived by their pagan neighbors as disrupting the relationship between the divine and the community, on which civic welfare depended. Early examples of persecution of Christians include the Acts of the Apostles, which portrays Saint Stephen as being killed by a mob in Jerusalem, while Paul writes that he himself had persecuted Christians prior to his vision of Christ. Additionally, Tacitus wrote that Emperor Nero blamed Christians for the Great Fire of Rome in 64 AD. In the following centuries, Church Fathers recorded accusations that Christians were responsible for droughts, famines, and plagues. Nevertheless, before the mid-3rd century, persecutions were often reactive, sporadic and local. This changed in 249, when the emperor Decius, who ruled the empire following a long period of instability, ordered all residents of the empire (except Jews) to perform a sacrifice to the Roman gods. Jews had long been excused on the basis of ancestral custom in ways that Christians, lacking any such established tradition, were not. The Diocletianic Persecution beginning in 303 was particularly severe; Christians were accused of attracting demons that disrupted traditional cult practices and threatened public order, and were subjected to confiscations, destruction of buildings, expulsions, imprisonment, and demands for sacrifice. The situation changed under Constantine (r. 306–337), who granted imperial support to Christianity, though under his rule and that of his successors, forms deemed heretical were suppressed.
Spread in the Roman Empire
Christianity spread to Aramaic-speaking peoples along the Mediterranean coast and also to the inland parts of the Roman Empire and beyond that into the Parthian Empire and the later Sasanian Empire, including Mesopotamia, which was dominated at different times and to varying extents by these empires. The presence of Christianity in Africa began in the middle of the 1st century in Egypt and by the end of the 2nd century in the region around Carthage. Mark the Evangelist is claimed to have started the Church of Alexandria in about 43 AD; various later churches claim this as their own legacy, including the Coptic Orthodox Church. Important Africans who influenced the early development of Christianity include Tertullian, Clement of Alexandria, Origen of Alexandria, Cyprian, Athanasius, and Augustine of Hippo.
King Tiridates III made Christianity the state religion in Armenia in the early 4th century, making Armenia the first officially Christian state. It was not an entirely new religion in Armenia, having penetrated into the country from at least the third century, but it may have been present even earlier.
Constantine I was exposed to Christianity in his youth, and throughout his life his support for the religion grew, culminating in baptism on his deathbed. During his reign, state-sanctioned persecution of Christians was ended with the Edict of Toleration in 311 and the Edict of Milan in 313. At that point, Christianity was still a minority belief, comprising perhaps only 5% of the Roman population. Influenced by his adviser Mardonius, Constantine's nephew Julian unsuccessfully tried to suppress Christianity. On 27 February 380, Theodosius I, Gratian, and Valentinian II issued the Edict of Thessalonica establishing Nicene Christianity as the State church of the Roman Empire. As soon as it became connected to the state, Christianity grew wealthy; the Church solicited donations from the rich and could now own land.
Constantine was also instrumental in the convocation of the First Council of Nicaea in 325, which sought to address Arianism and formulated the Nicene Creed, which is still used by in Catholicism, Eastern Orthodoxy, Lutheranism, Anglicanism, and many other Protestant churches. Nicaea was the first of a series of ecumenical councils, which formally defined critical elements of the theology of the Church, notably concerning Christology. The Church of the East did not accept the third and following ecumenical councils and is still separate today by its successors (Assyrian Church of the East).
In terms of prosperity and cultural life, the Byzantine Empire was one of the peaks in Christian history and Christian civilization, and Constantinople remained the leading city of the Christian world in size, wealth, and culture. There was a renewed interest in classical Greek philosophy, as well as an increase in literary output in vernacular Greek. Byzantine art and literature held a preeminent place in Europe, and the cultural impact of Byzantine art on the West during this period was enormous and of long-lasting significance. The later rise of Islam in North Africa reduced the size and numbers of Christian congregations, leaving in large numbers only the Coptic Church in Egypt, the Ethiopian Orthodox Tewahedo Church in the Horn of Africa and the Nubian Church in the Sudan (Nobatia, Makuria and Alodia).
With the decline and fall of the Roman Empire in the West, the papacy became a political player, first visible in Pope Leo's diplomatic dealings with Huns and Vandals. The church also entered into a long period of missionary activity and expansion among the various tribes. While Arianists instituted the death penalty for practicing pagans (see the Massacre of Verden, for example), Catholicism also spread among the Hungarians, the Germanic, the Celtic, the Baltic and some Slavic peoples.
Around 500, Christianity was thoroughly integrated into Byzantine and Kingdom of Italy culture and Benedict of Nursia set out his Monastic Rule, establishing a system of regulations for the foundation and running of monasteries. Monasticism became a powerful force throughout Europe, and gave rise to many early centers of learning, most famously in Ireland, Scotland, and Gaul, contributing to the Carolingian Renaissance of the 9th century.
In the 7th century, Muslims conquered Syria (including Jerusalem), North Africa, and Spain, converting some of the Christian population to Islam, including some of the Christian populations in pre-Islamic Arabia, and placing the rest under a separate legal status. Part of the Muslims' success was due to the exhaustion of the Byzantine Empire in its decades long conflict with Persia. Beginning in the 8th century, with the rise of Carolingian leaders, the Papacy sought greater political support in the Frankish Kingdom.
The Middle Ages brought about major changes within the church. Pope Gregory the Great dramatically reformed the ecclesiastical structure and administration. In the early 8th century, iconoclasm became a divisive issue, when it was sponsored by the Byzantine emperors. The Second Ecumenical Council of Nicaea (787) finally pronounced in favor of icons. In the early 10th century, Western Christian monasticism was further rejuvenated through the leadership of the great Benedictine monastery of Cluny.
High and Late Middle Ages
In the West, from the 11th century onward, some older cathedral schools became universities (see, for example, University of Oxford, University of Paris and University of Bologna). Previously, higher education had been the domain of Christian cathedral schools or monastic schools (Scholae monasticae), led by monks and nuns. Evidence of such schools dates back to the 6th century AD. These new universities expanded the curriculum to include academic programs for clerics, lawyers, civil servants, and physicians. The university is generally regarded as an institution that has its origin in the Medieval Christian setting.
Accompanying the rise of the "new towns" throughout Europe, mendicant orders were founded, bringing the consecrated religious life out of the monastery and into the new urban setting. The two principal mendicant movements were the Franciscans and the Dominicans, founded by Francis of Assisi and Dominic, respectively. Both orders made significant contributions to the development of the great universities of Europe. Another new order was the Cistercians, whose large, isolated monasteries spearheaded the settlement of former wilderness areas. In this period, church building and ecclesiastical architecture reached new heights, culminating in the orders of Romanesque and Gothic architecture and the building of the great European cathedrals.
Christian nationalism emerged during this era in which Christians felt the desire to recover lands in which Christianity had historically flourished. From 1095 under the pontificate of Urban II, the First Crusade was launched. These were a series of military campaigns in the Holy Land and elsewhere, initiated in response to pleas from the Byzantine Emperor Alexios I for aid against Turkish expansion. The Crusades ultimately failed to stifle Islamic aggression and even contributed to Christian enmity with the sacking of Constantinople during the Fourth Crusade.
The Christian Church experienced internal conflict between the 7th and 13th centuries that resulted in a schism between the Latin Church of Western Christianity branch, the now-Catholic Church, and an Eastern, largely Greek, branch (the Eastern Orthodox Church). The two sides disagreed on a number of administrative, liturgical and doctrinal issues, most prominently Eastern Orthodox opposition to papal supremacy. The Second Council of Lyon (1274) and the Council of Florence (1439) attempted to reunite the churches, but in both cases, the Eastern Orthodox refused to implement the decisions, and the two principal churches remain in schism to the present day. However, the Catholic Church has achieved union with various smaller eastern churches.
In the thirteenth century, a new emphasis on Jesus' suffering, exemplified by the Franciscans' preaching, had the consequence of turning worshippers' attention towards Jews, on whom Christians had placed the blame for Jesus' death. Christianity's limited tolerance of Jews was not new—Augustine of Hippo said that Jews should not be allowed to enjoy the citizenship that Christians took for granted—but the growing antipathy towards Jews was a factor that led to the expulsion of Jews from England in 1290, the first of many such expulsions in Europe.
Beginning around 1184, following the crusade against Cathar heresy, various institutions, broadly referred to as the Inquisition, were established with the aim of suppressing heresy and securing religious and doctrinal unity within Christianity through conversion and prosecution.
Modern era
Reformation and response
The 15th-century Renaissance brought about a renewed interest in ancient and classical learning. During the Reformation, Martin Luther posted the Ninety-five Theses 1517 against the sale of indulgences. Printed copies soon spread throughout Europe. In 1521 the Edict of Worms condemned and excommunicated Luther and his followers, resulting in the schism of the Western Christendom into several branches.
Other reformers like Zwingli, Oecolampadius, Calvin, Knox, and Arminius further criticized Catholic teaching and worship. These challenges developed into the movement called Protestantism, which repudiated the primacy of the pope, the role of tradition, the seven sacraments, and other doctrines and practices. The Reformation in England began in 1534, when King Henry VIII had himself declared head of the Church of England. Beginning in 1536, the monasteries throughout England, Wales and Ireland were dissolved.
Thomas Müntzer, Andreas Karlstadt and other theologians perceived both the Catholic Church and the confessions of the Magisterial Reformation as corrupted. Their activity brought about the Radical Reformation, which gave birth to various Anabaptist denominations.
Partly in response to the Protestant Reformation, the Catholic Church engaged in a substantial process of reform and renewal, known as the Counter-Reformation or Catholic Reform. The Council of Trent clarified and reasserted Catholic doctrine. During the following centuries, competition between Catholicism and Protestantism became deeply entangled with political struggles among European states.
Meanwhile, the discovery of America by Christopher Columbus in 1492 brought about a new wave of missionary activity. Partly from missionary zeal, but under the impetus of colonial expansion by the European powers, Christianity spread to the Americas, Oceania, East Asia and sub-Saharan Africa.
Throughout Europe, the division caused by the Reformation led to outbreaks of religious violence and the establishment of separate state churches in Europe. Lutheranism spread into the northern, central, and eastern parts of present-day Germany, Livonia, and Scandinavia. Anglicanism was established in England in 1534. Calvinism and its varieties, such as Presbyterianism, were introduced in Scotland, the Netherlands, Hungary, Switzerland, and France. Arminianism gained followers in the Netherlands and Frisia. Ultimately, these differences led to the outbreak of conflicts in which religion played a key factor. The Thirty Years' War, the English Civil War, and the French Wars of Religion are prominent examples. These events intensified the Christian debate on persecution and toleration.
In the revival of neoplatonism Renaissance humanists did not reject Christianity; quite the contrary, many of the greatest works of the Renaissance were devoted to it, and the Catholic Church patronized many works of Renaissance art. Much, if not most, of the new art was commissioned by or in dedication to the Church. Some scholars and historians attribute Christianity to having contributed to the rise of the Scientific Revolution. Many well-known historical figures who influenced Western science considered themselves Christian such as Nicolaus Copernicus, Galileo Galilei, Johannes Kepler, Isaac Newton and Robert Boyle.
Post-Enlightenment
In the era known as the Great Divergence, when in the West, the Age of Enlightenment and the Scientific Revolution brought about great societal changes, Christianity was confronted with various forms of skepticism and with certain modern political ideologies, such as versions of socialism and liberalism. Events ranged from mere anti-clericalism to violent outbursts against Christianity, such as the dechristianization of France during the French Revolution, the Spanish Civil War, and certain Marxist movements, especially the Russian Revolution and the persecution of Christians in the Soviet Union under state atheism.
Especially pressing in Europe was the formation of nation states after the Napoleonic era. In all European countries, different Christian denominations found themselves in competition to greater or lesser extents with each other and with the state. Variables were the relative sizes of the denominations and the religious, political, and ideological orientation of the states. Urs Altermatt of the University of Fribourg, looking specifically at Catholicism in Europe, identifies four models for the European nations. In traditionally Catholic-majority countries such as Belgium, Spain, and Austria, to some extent, religious and national communities are more or less identical. Cultural symbiosis and separation are found in Poland, the Republic of Ireland, and Switzerland, all countries with competing denominations. Competition is found in Germany, the Netherlands, and again Switzerland, all countries with minority Catholic populations, which to a greater or lesser extent identified with the nation. Finally, separation between religion (again, specifically Catholicism) and the state is found to a great degree in France and Italy, countries where the state actively opposed itself to the authority of the Catholic Church.
The combined factors of the formation of nation states and ultramontanism, especially in Germany and the Netherlands, but also in England to a much lesser extent, often forced Catholic churches, organizations, and believers to choose between the national demands of the state and the authority of the Church, specifically the papacy. This conflict came to a head in the First Vatican Council, and in Germany would lead directly to the Kulturkampf.
Christian commitment in Europe dropped as modernity and secularism came into their own, particularly in the Czech Republic and Estonia, while religious commitments in America have been generally high in comparison to Europe. Changes in worldwide Christianity over the last century have been significant, since 1900, Christianity has spread rapidly in the Global South and Third World countries. The late 20th century has shown the shift of Christian adherence to the Third World and the Southern Hemisphere in general, with the West no longer the chief standard bearer of Christianity. Approximately 7 to 10% of Arabs are Christians, most prevalent in Egypt, Syria and Lebanon.
Beliefs
While Christians worldwide share basic convictions, there are differences of interpretations and opinions of the Bible and sacred traditions on which Christianity is based. Christianity encompasses various movements of Christian theology, the main ones being conservative fundamentalist or moderate, liberal and progressive.
Creeds
Concise doctrinal statements or confessions of religious beliefs are known as creeds. They began as baptismal formulae and were later expanded during the Christological controversies of the 4th and 5th centuries to become statements of faith. "Jesus is Lord" is the earliest creed of Christianity and continues to be used, as with the World Council of Churches.
The Apostles' Creed is the most widely accepted statement of the articles of Christian faith. It is used by a number of Christian denominations for both liturgical and catechetical purposes, most visibly by liturgical churches of Western Christian tradition, including the Latin Church of the Catholic Church, Lutheranism, Anglicanism, and Western Rite Orthodoxy. It is also used by Presbyterians, Methodists, and Congregationalists.
This particular creed was developed between the 2nd and 9th centuries. Its central doctrines are those of the Trinity and God the Creator. Each of the doctrines found in this creed can be traced to statements current in the apostolic period. The creed was apparently used as a summary of Christian doctrine for baptismal candidates in the churches of Rome. Its points include:
Belief in God the Father, Jesus Christ as the Son of God, and the Holy Spirit
The death, descent into hell, resurrection and ascension of Christ
The holiness of the Church and the communion of saints
Christ's second coming, the Day of Judgement and salvation of the faithful
The Nicene Creed was formulated, largely in response to Arianism, at the Councils of Nicaea and Constantinople in 325 and 381 respectively, and ratified as the universal creed of Christendom by the First Council of Ephesus in 431.
The Chalcedonian Definition, or Creed of Chalcedon, developed at the Council of Chalcedon in 451, though rejected by the Oriental Orthodox, taught Christ "to be acknowledged in two natures, inconfusedly, unchangeably, indivisibly, inseparably": one divine and one human, and that both natures, while perfect in themselves, are nevertheless also perfectly united into one person.
