He brought him to Jesus. Jesus looked at him, and said, "You are Simon the son of Jonah. You shall be called Cephas" (which is by interpretation, Peter).

 In the Old Testament a change of name often denoted a new relationship with God. For instance, Jacob became Israel ( Genesis 32:28), and Abram became Abraham ( Genesis 17:5) when they entered into a new relationship with God. When a man enters into a new relationship with God, it is as if life began all over again and he became a new man, so that he needs a new name. 