Luke 6:15

‘And Matthew and Thomas, and James the son of Alphaeus, and Simon who was called Zelotes, (or ‘the zealous one'),'

Matthew is Levi, the son of Alphaeus, who was the toll collector mentioned in Luke 5:27 (see Matthew 10:3). Thomas occasionally came into prominence (John 11:16; John 14:5) but is best known for not having been present when the other equally doubting Apostles met the risen Lord in Jerusalem (John 20:24) and was therefore rather unfairly dubbed ‘Doubting Thomas'. James the son of Alphaeus (who may be the James the Little of Mark 15:40) may have been brother to Levi the son of Alphaeus (Mark 2:14), although the name Alphaeus was fairly common. Simon is also called Zelotes, which means ‘the zealous one'. It may be that he established a reputation for over-eagerness. The term Zealot, signifying insurrectionists against Rome, did not arise until later, although it is possible that the term was affectionately applied to him later by the Apostles because of his hotheadedness.