Sometimes I amuse myself by imagining Jesus and the Apostles in situations they might see if they grew up in the America that I know and love. When I was a kid one of the things I did was run around in knee high grass stuffing grasshoppers in a glass jar, so I imagined James and John (the Apostle) headed home with a clay pot full of grasshoppers and James (in his wisdom) warned his younger brother to, "Keep them away from John [the Baptist]. He'll eat anything!"
This all comes to mind because of the familial relationships the significant figures of Christianity had to each other and to Jesus. Of course everyone knows John the Baptist was the son of the aunt of Mary. James the Elder and John the Apostle were brothers who's mother was the sister of Mary (which also sheds some light on the incident of Jesus leaving Mary under John's care at the foot of the cross). Peter and Andrew were the sons of Zebedee who was related to Joseph. Joseph of Aramethea was, allegedly, the great uncle of Mary. According to Eusebius, Jude was the brother of Jesus. This must have been a step brother which has been speculated by a few people to be from Joseph who was a widower before he married Mary. James the Younger may also have been a step brother, but that is in dispute among scholars. Of course not all the apostles were related to Jesus. Judas and Matthew definately had no blood relation of any notability, but that is not to say they never knew each other.
Imagine Jesus and the Apostles at Thanksgiving Day dinner, all at the kids' table and Jesus says, "What are people saying this gravy is made of?" They said in reply, "Beef, others chicken, still others say it is made of power." And he asked them, "But what do you say it is?" Peter said to him in reply, "It is turkey gravy." And he answered, "Blessed are you Simon son of Jonah, for this has not been revealed to you by man...your mother told you!" These things must make one wonder about Jesus' interactions with the future Apostles as children. Did the kids all know where Jesus was when Mary and Joseph looked for him for three days in Jerusalem? In all the sermons I ever heard on the baptism of the Lord I was always given the impression that John had never met Jesus before, but this seems unreasonable in light of their relationship as cousins. It seems that they should have spent a lot of time together as children and when the Gospel accounts of the Baptism are read there is no indication of unfamiliarity, quite the contrary, in fact they appear to know each other well.
This all makes fully half of the Apostles step brothers or first cousins of Jesus, and it tends to make me wonder if Jesus was close childhood friends with all the Apostles. While it may be interesting to think about we will not know for certain any time on this side of the Jordan.