Once a person makes a commitment to be on God's side, God locks Him in, so to speak. That is predestination. However, if a person on God's side pulls himself free from God, he was never predestined in the first place.
Why does your god have to lock him in, so to speak? Didn't your god know from the creation of the universe this person would make the commitment?
You speak often of limitations of your god's magic.
You still don't understand the idea of children. Children have the attributes of their parents, even though those attributes aren't developed, yet.