The history of early Christianity covers Christianity from its origins to the First Council of Nicaea in 325.
The first part of the period, during the lifetimes of the Twelve Apostles, is traditionally believed to have been initiated by the Great Commission of Jesus (though some scholars dispute its historicity), and is called the Apostolic Age. The earliest followers of Jesus composed an apocalyptic, Second Temple Jewish sect, which historians refer to as Jewish Christianity. Though Paul's influence on Christian thinking is said to be more significant than any other New Testament author, the relationship of Paul of Tarsus and Judaism is still disputed today. Early Christianity gradually grew apart from Judaism during the first two centuries and established itself as a predominantly gentile religion in the Roman Empire.
In the Ante-Nicene Period (literally before the First Council of Nicaea in 325), following the Apostolic Age, both incredible diversity and unifying characteristics lacking in the apostolic period emerged simultaneously. Part of the unifying trend was an increasingly harsh rejection of Judaism and Jewish practices. By the beginning of the Nicene period, the Christian faith had spread throughout Western Europe and the Mediterranean Basin, and to North Africa and the East, see Early centers of Christianity.
Early Christianity is the period of Christianity preceding the First Council of Nicaea in 325. It is typically divided into the Apostolic Age and the Ante-Nicene Period (from the Apostolic Age until Nicea).
The first Christians, as described in the first chapters of the Acts of the Apostles, were all Jewish, either by birth, or conversion for which the biblical term proselyte is used, and referred to by historians as the Jewish Christians. The early Gospel message was spread orally; probably in Aramaic, but almost immediately also in Greek. The New Testament's Book of Acts and Epistle to the Galatians record that the first Christian community was centered in Jerusalem and its leaders included Peter, James, and John.Paul of Tarsus, after his conversion to Christianity, claimed the title of "Apostle to the Gentiles". Paul's influence on Christian thinking is said to be more significant than that of any other New Testament author. By the end of the 1st century, Christianity began to be recognized internally and externally as a separate religion from Judaism which itself was refined and developed further in the centuries after the destruction of the Second Jerusalem Temple.