The central teachings of traditional Christianity are that Jesus is the Son of God, the second person of the Trinity of God the Father, the Son, and the Holy Spirit; that his life on earth, his crucifixion, resurrection, and ascension into heaven are proof of God's love for humanity and God's forgiveness of human sins; and that by faith in Jesus one may attain salvation and eternal life (see creed). This teaching is embodied in the Bible, specifically in the New Testament, but Christians accept also the Old Testament as sacred and authoritative Scripture.
Christian ethics derive to a large extent from the Jewish tradition as presented in the Old Testament, particularly the Ten Commandments, but with some difference of interpretation based on the practice and teachings of Jesus. Christianity may be further generally defined in terms of its practice of corporate worship and rites that usually include the use of sacraments and that are usually conducted by trained clergy within organized churches. There are, however, many different forms of worship, many interpretations of the role of the organized clergy, and many variations in polity and church organization within Christianity.
In the two millennia of its history Christianity has been divided by schism and roiled by heresy, based on doctrinal and organizational differences. Today there are three broad divisions, Roman Catholic, Orthodox Eastern, and Protestant; but within the category of Protestantism, there is a particularly large number of divergent denominations. Because of the complexity of these differences this article will describe the history of Christianity only to 1054, when the schism between Eastern and Western churches became final. Separate articles detail the history and doctrines of the Roman Catholic Church and Orthodox Eastern Church and of the other churches of ancient origin, the Armenian Church, the Coptic Church (see Copts), the Jacobite Church, and the Nestorian Church. In the 16th cent. another major schism took place in the Western Church with the Protestant Reformation. For the Protestant churches, see Protestantism and articles on the separate churches. For the 20th-century movement that seeks to end the divisiveness in Christianity and achieve reunion, see ecumenical movement.
Christianity is in a direct sense an offshoot of Judaism, because Jesus and his immediate followers were Jews living in Palestine and Jesus was believed by his followers to have fulfilled the Old Testament prophecies of the Messiah. Following a trend of proselytization in the Judaism of that period Christianity was from its beginnings expansionist. Its early missionaries (the most notable of whom was St. Paul, who was also responsible for the formulation of elements of Christian doctrine) spread its teachings in Asia Minor, Alexandria, Greece, and Rome. Missions have remained a major element in Christianity to the present day.
For the first three centuries of Christianity, history is dependent on apologetic and religious writings; there are no chronicles (see patristic literature). Historians differ greatly on how far back the 4th-century picture of the church (which is quite clear) can be projected, especially respecting organization by bishops (each bishop a monarch in the church of his city), celebration of a liturgy entailing a sacrament and a sacrifice, and claims by the bishop of Rome to be head of all the churches (see papacy). There is evidence for these features in the 2d cent. A first problem for Christians was how to resist attempts to interpret the new beliefs in pagan terms (e.g., Gnosticism). The earliest sectarian deviations were those of Marcion and of Montanus (2d cent.). They were handled resolutely by the church; the teachers of novelty were expelled (excommunicated).
For 250 years it was a martyrs' church; the persecutions were fueled by the refusal of Christians to worship the state and the Roman emperor. There were persecutions under Nero, Domitian, Trajan and the other Antonines, Maximin, Decius, Valerian, and Diocletian and Galerius; Decius ordered the first official persecution in 250. In 313, Constantine I and Licinius announced toleration of Christianity in the Edict of Milan. In the East the church passed from persecution directly to imperial control (caesaropapism), inaugurated by Constantine, enshrined later in Justinian's laws, and always a problem for the Orthodox churches. In the West the church remained independent because of the weakness of the emperor and the well-established authority of the bishop of Rome.
For 300 years after A.D. 275 the church in the East was occupied with doctrinal controversies—Arianism, Nestorianism, Monophysitism, and Monotheletism. These arguments concerned the manner in which Jesus is both divine and human. Decisions were made at a series of general councils of bishops (see council, ecumenical); at them was composed the Nicene Creed. These centuries saw a series of Christian writers of unequaled influence (the Fathers of the Church): Origen, St. Athanasius, St. Basil the Great, St. Gregory of Nyssa, St. Gregory Nazianzen, St. John Chrysostom, and Theodoret writing in Greek; St. Ambrose, St. Jerome, and St. Augustine writing in Latin. Origen and St. Jerome had a special role in the church's work of determining and preserving the text of the Bible.
From the 3d cent. monasticism was one element of the church. It was first organized by St. Basil. In the West monasticism was central to the missionary work of St. Martin (Gaul, 4th cent.) and St. Patrick (Ireland, 5th cent.). It received definitive shape from St. Benedict and St. Gregory the Great, who thereby generated a mode of life of continuing vitality in the Roman Catholic Church.
German invasions slowed the conversion of Western Europe (e.g., that of England was recommenced in the 6th cent.). Most of the first invaders were converted to Arian Christianity, but the pagan Franks (with Clovis) adopted orthodox Christianity, a fact that probably helped to consolidate their rule. Out of this kingdom came Pepin and Charlemagne, who, by alliance with the papacy and proclamation of an empire (800), charted an ideal of the Middle Ages.
In the 7th and 8th cent. the Eastern Church lost to Islam all Asia except Asia Minor. Alienation from the West was exacerbated by the bitter struggle over iconoclasm; ecclesiastical animosity between Rome and Constantinople came to a head in the schism of the 9th cent. This schism centered on the addition of the Filioque to the Nicene Creed (see creed) in the West and on the western church's use of unleavened bread in the celebration of the mass and insistence on clerical celibacy. The division between East and West grew wider and attained a sort of legal permanence in 1054 (see Leo IX, Saint). Eastern and Western Christendom were already in the 9th cent. two different cultures; their one common tie was the Christian doctrine—even worship and practices were very different. From this time it is customary to distinguish Christian history in its Eastern and Western streams as that of the Orthodox Eastern Church and Roman Catholic Church.
See J. Lebreton and J. Zeiller, A History of the Early Church (4 vol., 1944-46; repr. 1962); H. Lietzmann, The History of the Early Church (4 vol., tr. 1961; repr. 1967); A. Finkel, The Pharisees and the Teacher of Nazareth (1964); H. Marrou et al., The Christian Centuries (1964); J. G. Davies, The Early Christian Church (1965); H. Chadwick, The Early Church (1967); R. M. Grant, Augustus to Constantine (1970); R. W. Southern, Western Society and the Church in the Middle Ages (1970); R. Fletcher, The Barbarian Conversion (1998).
Outside of Christianity, the term "born again" is occasionally used to describe beliefs characterised by renewal, resurgence or return.
Some Christian denominations hold that a person must be born again in some sense to be a Christian and are explicit about this with their use of the words. The term is most popular in the USA, and is making inroads into other parts of the world. The meaning of born again varies among Christian traditions as how literally or symbolically they take the term and how central it is within their belief system:
For believers in the third group above being 'Born Again' does not require being baptized in water submersion nor being filled with the holy spirit, for them these are extra events that are only for those who are already 'saved' and hence would be going to heaven when they die. "According to your confession of faith, I now baptize you in the name of the father the son and the holy spirit" - Baptist pastor prior to water immersion. "... Forgive me for I am a sinner...I accept you [Jesus] as my lord and savior..." excerpt from a prayer of repentance used by mainstream and pentecostal churches to receive salvation.
In theology, the study of salvation is called soteriology. The idea of being "born again" carries with it the soteriological idea that a Christian is a "new creation," given a fresh start by the action of God, freed from a sinful past life and able to begin a "new life" in relationship with Christ via the Holy Spirit. The Apostle Paul described it as such:
John Wesley and Christians associated with early Methodism referred to the "born again" experience as "the New Birth." They based this on the previously cited biblical passages and including the following:
According to the Gospel of John, chapter 3, Jesus originated the term "born again" while teaching Nicodemus, a rabbi of the Jewish sect known as the Pharisees. The traditional Jewish understanding of the promise of salvation was that being rooted in "the seed of Abraham" referred to physical (genetic) lineage from Abraham. Jesus explained to Nicodemus that this doctrine was in error—that one must be born a second time through spiritual rebirth. Jesus' discourse with Nicodemus established the Christian belief that all human beings—whether Jew or Gentile—must be "born again" of the spiritual seed of Christ.
The Apostle Paul further reinforced this understanding in his epistle to the Galatians, chapter 3, and in .
In recent history, born again is a term that has been associated with evangelical renewal since the late 1960s, first in the United States and then later around the world. Associated perhaps initially with Jesus People and the Christian counterculture, born again came to refer to an intense conversion experience, and was increasingly used as a term to identify devout believers. By the mid 1970s, born again Christians were increasingly referred to in the mainstream media as part of the Born Again Movement. Based on most exit polls of the 2004 US presidential election, born again Christians were a major factor in the re-election of George W. Bush.
In 1976 a book titled Born Again was published by Watergate conspirator and convicted felon Charles Colson. It describes his path to faith in conjunction with his criminal imprisonment and played a significant role in solidifying "Born Again" identity as a cultural construct in the U.S. The term was sufficiently prevalent that during the year's Presidential campaign Jimmy Carter described himself as born again, notably in the first Playboy magazine interview of a U.S. Presidential candidate. Modern musicians Rev. Little Richard Penniman, Mark Farner, Dan Peek, Donna Summer, Bob Dylan., Kerry Livgren, Dave Hope, Dave Mustaine, Nicko McBrain, Roger McGuinn, Johnny Cash, Brian Welch, Keith Farley and Alice Cooper were artists whose born again conversions had an impact on modern culture. Others such as James Cash Penney, C. S. Lewis, WWE superstar Shawn Michaels, Charlie Daniels, and Mr. T are also mentioned as being born again. Former Alabama governor and US presidential candidate George Wallace became born again in the late 70s, which led him to apologize for his earlier segregationist views.