The apostles were 12 men chosen by Jesus Christ (c. 6 B.C.–C. A.D. 30) to be his close followers. The apostles helped spread the word that they believed Jesus to be the Son of God. Matthew 10:1 explains that Jesus gave the 12 authority to drive out unclean spirits and to cure every kind of illness.

In Matthew 10:2–4, the names of the 12 apostles are given as Simon Peter (who is later simply called Peter), Andrew, James, John, Philip, Bartholomew, Thomas, Matthew, James the son of Alphaeus, Thaddaeus, Simon the Zealot, and Judas Iscariot. But the lists of apostles found in Luke 6:13–16 and in Acts 1:13 differ from that found in Matthew. While both Luke and Acts cite (Simon) Peter, Andrew, James, John, Philip, Bartholomew, Thomas, Matthew, James the son of Alphaeus, Simon the Zealot, and Judas Iscariot, they do not name Thaddaeus, but rather Judas the son of James. In other words, the lists agree on 11 of the 12 names.

After Judas Iscariot betrayed Jesus Christ, Matthias was chosen by the apostles to take his place (this is described in Acts 1:21–26). He was considered eligible since, like the 11 remaining apostles, he accompanied Jesus from the time of Jesus’s baptism until “the day he was taken up from us.”