One of the main reasons we can have for believing in God is that, If God exists, we have a good explanation for the existence of an orderly and relatively life-friendly universe such as we find ourselves in. But this is only true if God’s will is not completely free. To see why this is so, let us consider two sets of possible worlds: The first is the set of all possible worlds, and the second is the set of all possible worlds where God exists. Now, my question is this: Does God’s nature impose any constraints on which possible worlds He can actualize? Of course, if God exists, it follows that God cannot actualize any possible worlds where He does not exist, and so in this sense the answer to my question is surely “yes”. But are there any constraints besides this? Or is the set of worlds in which God exists, apart from His existence, exactly the same as the set of worlds in which God does not exist? To clarify: Is God’s existence compatible with possible worlds which are disordered, hostile to life, and which perhaps contain no sentient beings at all? If it is, the existence of God cannot explain the order and life-friendliness of the universe because those characteristics are no more likely if God exists than if He doesn’t. But if God’s nature does impose constraints on which worlds God can actualize—constraints which, as above, rule out possible worlds which are too disorderly to accommodate life or sentience of any sort—then there are significant constraints on what God can will, for then God cannot actualize just any possible world. God’s will would not be completely free. This would not mean that God is “forced” to actualize only orderly, life-friendly worlds against His will, but rather that those are the only kinds of worlds God could desire to actualize. The upshot of our considerations is this: On the one hand, if God’s will is completely free, there are no constraints on which worlds God can actualize, and hence God’s existence does not explain the existence of an orderly, life-friendly universe. One of the main reasons we could have for believing that God exists would be undercut. On the other hand, if God’s nature does impose constraints on which worlds He can actualize, there are significant constraints on His free will, which may be considered unorthodox by many theists. Thus, if they wish to uphold the complete freedom of God’s will, they cannot endorse teleological and/or cosmological arguments for God’s existence. For such arguments presuppose that God’s existence would explain the existence of an orderly, life-friendly universe, but we have seen that this would not be so if God’s will were completely free.
 I am supposing that God does not exist in all possible worlds (assuming for the sake of argument that He exists). If you disagree, consider two different ways of envisioning the space of all possible worlds: One in which God exists in all, and another in which God exists in none.