It was at this time that He went off to the mountain to pray, and He spent the whole night in prayer to God.
And when day came, He called His disciples to Him and chose twelve of them, whom He also named as apostles: Simon, whom He also named Peter, and Andrew his brother; and James and John; and Philip and Bartholomew; and Matthew and Thomas; James the son of Alphaeus, and Simon who was called the Zealot; Judas the son of James, and Judas Iscariot, who became a traitor.
Jesus relied on His Father.
The Traitor was not a Mistake.
He was not a mistake that somehow got into the group unnoticed. From the outside, he looked just like the rest of the disciples. His covetous, unbelieving heart was unknown to the other apostles, but it was not unknown to God. From the beginning, Jesus knew that "not all of them were clean" (John 13:11) and that one of them would betray him. He knew that one of them was a "plant from Satan." (Matt. 13:38) From the very beginning, the choosing of a traitor was to fulfill the words given to the prophets made about Messiah. (Luke 22:22) The choosing of the Traitor was eventually going to lead Jesus to the Cross: the purpose for which He had come. (John 12:27)
I don't often consider that a Judas Iscariot might be as much a part of the answer as a Peter and James and John--or that the long-range answer to my prayer is the way of the Cross.
Jesus did good to His enemies.
Jesus gives the Sermon on the Mount. His words take on a new understanding when seen in light of Judas: "Love your enemies. Do good to those who hate you, bless those who curse you, pray for those who mistreat you." This wasn't pious advice delivered at a Temple teaching. It was the daily example of how Jesus treated a close friend who was going to sell Him to His enemies to be crucified for 30 pieces of silver.