It forms the second part of Christian Bibles following "the Old Testament," which in Protestant Bibles contains the same books as Jewish Bibles but in a different order.
Catholic and Orthodox Christian Bibles have their own orders of "the Old Testament" in which other ancient books are interspersed.
Thus the fourth gospel's anonymous writer claims to be recording the testimony of a source figure identified only as "the beloved disciple" of Jesus.
In broad terms, these gospels present similar versions of Jesus' arrest, condemnation, death, and resurrection, but the Gospel of John has a markedly different account of earlier events and of the content of Jesus' teaching.
Consequently, the first three are commonly termed the "Synoptic Gospels" because of the ease with which they can be printed in parallel columns as a "synopsis." Matthew and Luke contain versions of the virgin birth of Jesus to Mary (Matthew: shortly before the death of Herod, i.e., 4 ) and Luke includes his visit to Jerusalem at age 12; otherwise only the last period of his adult life is featured (Luke: from age "about 30" on).
Next comes the Acts of the Apostles, which introduces itself as the continuation of the third gospel.
In it, "apostles" mostly refers strictly to 12 early close disciples of Jesus.
Acts begins with the last instructions of Jesus to his followers (after his resurrection), his ascent to heaven from the Mount of Olives, and their subsequent reception of the Holy Spirit.
Their attempts to win over other Jews lead to clashes with the authorities and to the dispersal of most of them elsewhere.
But then the appearance of Jesus himself in a vision to a certain Saul, who was their chief persecutor, turns Saul into an ardent follower.
The latter, now called Paul, makes a series of journeys to the Jewish Diaspora, where his preaching about Jesus causes divisions among Jews but has remarkable success among non-Jews, especially those previously close to Judaism.