Now according to the trinity god, jesus, and the holy spirit are one together to form a god. So three persons in one god.
Anyway, god supposedly became flesh, then lived on Earth, preached then was sacrificed and resurrected.
So if god was omnipotent and is all knowing, then he knew that he was going to die and rise again. As an immortal, he would never die. So in reality there was no sacrifice, since he knew he never was going to die.