I say that the Son, also known as the Logos (the Word), becomes incarnate so as to “participate” in creation. And while this is true, the fullness of his purpose involves the redemption of humankind. This phrase can sound vague, but imagine for a moment that our existence takes place in a sort of cosmic economy. Satan shifts the balance by seducing us to sin, which causes us to lose Eden. He himself has nothing to lose, because he has already and forever been banished from Heaven. Remember that he was once Lucifer, the highest of all angels, until, in primeval time, envy of God caused him to relinquish the beatific vision. His only satisfaction now, if you can call it that, is in causing strife and disorder throughout creation, and in seeing souls bring themselves into his realm. That he can do this only insofar as God allows him to do it — for Satan is a creature (pure spirit, but a creature no less) and in no way equal to God — is one of those mysteries or paradoxes that we sometimes encounter when we try to understand the way of things. Why does God allow evil to persist? Well, if he didn’t, we would be without free will, for there would be nothing for us to choose but that which God would have us choose. And that is not the way of God. He is not a tyrant.