Luke 6:12-19 The Calling of the Twelve

Jesus departed to the mountain to pray,
and he spent the night in prayer to God.
When day came, he called his disciples to himself,
and from them he chose Twelve, whom he also named Apostles:
Simon, whom he named Peter, and his brother Andrew,
James, John, Philip, Bartholomew,
Matthew, Thomas, James the son of Alphaeus,
Simon who was called a Zealot,
and Judas the son of James,
and Judas Iscariot, who became a traitor.

And he came down with them and stood on a stretch of level ground.
A great crowd of his disciples and a large number of the people
from all Judea and Jerusalem
and the coastal region of Tyre and Sidon
came to hear him and to be healed of their diseases;
and even those who were tormented by unclean spirits were cured.
Everyone in the crowd sought to touch him
because power came forth from him and healed them all.

In this passage we see Jesus' selection of the Twelve Apostles.  The likely reason for selection exactly twelve is because of the symbolic connection to the twelve tribes of Israel. We see a continuity of God's grace through Jesus' followers. The term Apostle comes from the Greek Apostlos which means to send. So Jesus' disciples are being sent on a mission to spread the Gospel. In this reading we also see how Jesus' ministered to the people by talking with them, teaching them, and healing them. This is the role of his apostles, to bring the Gospel to the people and also tend to their needs.