Christianity believes that God became a human being. God became a real, flesh-and-blood person, in every way just like we are. Christians call this person that resulted when God became a human being “Jesus.”
Christianity believes, though, that even when God became a human being in every way just like us, He did not cease to be God. During the time Jesus was on earth, God was a human being just like us; but at the same time, He was God.
This is “The Great Mystery of Christianity.” How could God become a human being just like us, but at the same time still be God? We can’t understand it, and we can’t explain it. And so we don’t try to.
If we do try to explain it, we come up with things that don’t make sense. We end up like many Christians, trying to say that God had some sort of offspring that He sent here to earth. But Christianity has never made sense when it tried to say that. And so, we’ll just say that Jesus was God as a human being on earth, and we’ll leave it at that.
It’s vital to understand that Christianity maintains God did in fact really become a human being. It’s not just that God somehow especially operated through a very good person. It’s not that God saw a really good person and decided to do some special things through that person. It’s not that there once was a really good person who got especially close to God.
Christianity says God really did become a real person. Jesus was none other than God Himself as a genuine human being.