The commissioning of the Twelve Apostles during the ministry of Jesus is recorded in the Synoptic Gospels. After his resurrection, Jesus sent eleven of them (minus Judas Iscariot) by the Great Commission to spread his teachings to all nations. There is also an Eastern Christian tradition derived from the Gospel of Luke of seventy apostles. Paul the Apostle (Saul of Tarsus), not one of the twelve or the seventy but a later convert, "the apostle of the Gentiles",^{[Romans 11:13]} claimed a special commission from the resurrected Jesus, separate from the Great Commission given to the twelve. Paul did not restrict the term apostle to the twelve, he referred to his mentor Barnabas as an apostle. This restricted usage appears in Revelation. In modern usage, major missionaries are sometimes termed apostles, as in Saint Patrick, "Apostle of Ireland".

The sub-period of Early Christianity during the lifetimes of the apostles is called the Apostolic Age. In the 2nd century, association with the apostles was esteemed as evidence of authority and such churches are known as Apostolic Sees. Paul's epistles were accepted as scripture, and two of the four gospels were associated with apostles, as were other New Testament works. Various Christian texts, such as the Didache and the Apostolic Constitutions, were attributed to the twelve apostles. Bishops traced their lines of succession back to individual apostles, who were said to have dispersed from Jerusalem and established churches across great territories. Christian bishops have traditionally claimed authority deriving, by apostolic succession, from the twelve. Early Church Fathers that came to be associated with Apostles, such as Pope Clement I with Peter the Apostle, are referred to as Apostolic Fathers. The Apostles' Creed, popular in the West, was said to have been composed by the apostles themselves. The twelve apostles are also called the twelve disciples.