How could Jesus have existed in Heaven, before Adam? I thought Jesus only existed when he was born (from Mary)? I guess this is a point in which Muslims and Christians can never agree on. We both think we are correct. How anybody except Jesus is god, is beyond me?! Let's assume you are correct, Jesus is god! Why would god be little himself by becoming human. It makes no sense? Why would he need to be crusified for our sins'. If he was god he can just forgive us of our sins' without having to be tortured or cursified.
Why would NOT He? No islamic conjectures please. Believe me I was in the same kind of denial about Jesus' deity before I truly studied the Scriptures.