If you were interviewing prospective apostles what would you be looking for? Somebody who was loyal, honest, trustworthy? What about Peter in the courtyard of the High Priest’s house? Would you look for somebody who knew their own limitations and did not overestimate their own strengths or abilities? What about Peter at the Last Supper, or trying to walk on the storm-tossed waters of the Sea of Galilee? Would you look for a person who was not ambitious for their own advancement? What about James and John wanting to sit on either side of Jesus when he came into his kingdom? Would you look for people who were direct and straightforward and not devious in any way? James did not approach Jesus directly with his request for promotion, he got his mother to do it for him. The choice Jesus makes is not because of what the disciples are but of what they will become.
The twelve represent the twelve tribes of the new Israel. The old Israel had delegated just the priestly tribe of Aaron for the worship of God, the new people formed around the twelve is to be entirely priestly characterized by vocation and election, not by heredity. The twelve are the foundation stones of the new Church because they were eyewitnesses to the whole of Jesus’ life from his baptism by John to his ascension. Chosen by Christ they are a special set of witnesses set apart not so much by what they see as by the fact that they are chosen to see. What they see comes to them as a gift, they are chosen to pass on this gift, to be part of the process of tradition, the process that can only go on within the group of witnesses.
The work of preaching is not a solitary task. It is not a function or a job which somebody can do simply because they have a talent for it, after all, many of the apostles do not seem to have had a special gift for it. An apostle receives a commission that comes directly from Christ through his Church. It is a mission that is always exercised in relation to others. The word itself means one who is sent. You cannot send yourself.