In Genesis 17 God changes Abram and Sarai's names.
"God also said to Abraham, "As for Sarai your wife, you are no longer to call her Sarai; her name will be Sarah." verse 15. Sarai means, 'my princess'. But God changed it to mean only 'Princess' because from her would come kings and queens.
I find it interesting how often God chose names for important people in the Bible. He chose John (the baptist), Jesus, Isaac, Ishmael, and he re-named Simon to Peter and Saul to Paul.
In heaven we will all be given a new name. I think this is pretty cool. I can't wait to find out what mine is. I would guess the name will tell something about our lives on earth or in heaven.
"He who has an ear, let him hear what the Spirit says to the churches. To him who overcomes, I will give some of the hidden manna. I will also give him a white stone with a new name written on it, known only to him who receives it." Rev. 2:17
A secret name between God and us. Amazing.