Was it necessary for God to create the universe? Put another way, does God have free will? Edwards, it turns out, affirmed that creation is a necessary output of the divine nature. What would necessitate the divine nature to create a contingent world? For Edwards, it is not the world itself that necessitates God because nothing non-existent can necessarily cause God to do anything, but rather, it is God’s natural desire to glorify Himself (or diffuse His goodness) that necessitates creation. So Edwards wants to maintain that (1) God does not need the universe but that (2) He nevertheless must create the universe. He thinks this makes sense because “Tis no argument of the emptiness or deficiency of a fountain that it is inclined to overflow” (Yale: Works, Vol. 8, 448). In other words, God is a perfect fountain that is already filled so it is in need of nothing else, and yet His goodness necessarily overflows.
This is not only nonsensical, it is heretical in effect (not in intention) because it undermines God’s aseity. I love Edwards, to be honest, and I always will, but he is just dangerously wrong here. Edwards believes that desire is not chosen, but the product of your predetermined nature. The divine nature is no exception. Whatever God desires is determined by His nature. So for Edwards, God has the property of “highly desiring to create this universe” in His nature. God necessarily acts in accordance to His highest desire, thus He necessarily creates the universe. If you tried to conceive of God without this property, you would not be conceiving of God proper but some lesser god because the divine nature necessarily has this property. God would not be God without it.
To think that God could not be God without having that property should sound absolutely ridiculous. Why must God desire to create a universe in order to be fully God? As Aquinas puts it, “Since, then, the divine goodness can be without other things, and, indeed, is in no way increased by other things, it is under no necessity to will other things from the fact of willing its own goodness” (Contra Gentiles, Ch 81, 2). The universe is contingent, so there is nothing in the universe that should necessitate this property in God. Nor should there be anything in God that necessitates the creation of something else. To have a desire of this kind is to lack something in your nature that must be fulfilled. You don’t desire what you already have. You only desire what you lack (e.g, our need for food). So if God must highly desire to create a universe, then He necessarily lacks something in His nature: namely the creation of the universe.
This entails that God needs to create the universe. Someone could object: “Well if God eternally created the universe, then He never lacked it.” This is false. Even if the universe was created eternally because God is outside of time, the universe is eternally co-extensive with God. In other words, the universe fulfills the property that God has eternally and therefore He is in need of that to be who He is. This is completely unacceptable. God has no need of anything external like creation (Acts 17:25), so Edwards’ view clearly undermines God’s aseity. The fountain analogy is useless because if a water fountain overflows, it is because it is finite. God is infinite, so His goodness cannot overflow like a fountain. The only sense in which God’s goodness can overflow is if God did not need to create but freely chose to create anyway.

Libertarian free will must be affirmed at least of God or God does not exist. A God that needs is not God by definition.