I was listening to an apologist recently who was trying to explain the problem of Hell. The apologist wanted to make clear that God did not want to send anyone to Hell, but that He had no choice because of our sinful nature. This struck me as something of a throwback to an earlier form of religion.
One of the hallmarks of polytheistic religion is how close the Gods are to humans. The Gods are usually just extremely powerful, wise humans. There is also always some kind of higher law above them that they cannot escape.
The Greek Gods were slaves to fate. The Norse Gods could not stop the coming of ragnarok (at least after the Norse were exposed to Christian apocalyptic thought). Most striking of all, the Hindu Gods were stuck dealing with karma and the cycle of death and rebirth.
Call this “the highest law,” or if you want to be pretentious, the “meta-divine realm.”
In theory, there is no “highest law” in Christianity. God is the ultimate and not bound by any restrictions. The danger here is practical: people might begin focusing on the highest law. This is what happened with Hinduism. Hinduism spawned many different sects that sought ways to escape the wheel of life and rebirth without the aid of the Gods, including Buddhism.
If this is the case, then God is not omnipotent. The laws governing purity are more powerful than He and He cannot alter them. He can attempt to work within the rules of the purity system by sacrificing his son and thereby making everyone who believes in Him pure. But he cannot simply declare that everyone is pure, or change the rules of purity so that impure beings are no longer repelled.
If this is the case, then perhaps humans would be better off focusing their attention on the law of purity. We could make an end run around God, defeating the system of purity the way that Buddhists attempt to remove themselves from the wheel of death and rebirth.