 Another route to the identity of God with his existence is via the divine necessity. Although it is true to say that a contingent being is one that exists in some, but not all, metaphysically possible worlds, that is not what makes a contingent being contingent. What makes a contingent being contingent is the real distinction in it between essence and existence. What makes an absolutely necessary being necessary, then, is the lack of such a distinction. God, who has his necessity from himself and not from another, is therefore identical to his existence. One can say, if one likes, that God exists in all metaphysically possible worlds, but that is true only because in God essence and existence are the same.  The divine simplicity is the ground of the divine necessity. Given the way our minds work, we cannot think of God without distinguishing between essence and existence; but that is our affair and not God’s. In reality, God is his existence. 