If one were to ask the question “why does a rock fall when released from the hand,” it would, no doubt, be a true yet odd answer to say that “God wills it.” Yet, we must not argue that indeed, the falling of the rock does not escape God’s providence. It certainly did not catch Him by surprise.
However, when asking the question, we are usually seeking the more proximate answer. To say that “the rock falls because of gravity,” that still hardly understood force that draws massive objects toward one another, is to in no way infringe upon God’s power and providence.
In fact, we could not believe in miracles if we did not believe in a normal order of the world, created by God, in which things had proximate causes. By this, I mean that, if we did not understand it to be that gravity is what caused a thing to fall to the ground, we would make no sense in saying that a levitation of an object is miraculous. It would simply be “that particular occasion” of God’s will. We could say that, in our experience, God seems to more often will a rock to fall than to levitate, but we could in no way make a distinction between the one being natural and the other being miraculous.
Miracles, by definition, do not destroy belief in a natural world, as many that reject the faith assume, but rather, presuppose it. Likewise, grace, that super-immanent power of God, does not destroy nature but perfects it, elevates it.
Once a miracle enters reality, it acts with reality. Miracles enter the world from without, but behave within it once present. Take the loaves and the fish. Once present, the loaves and the fish are “loaves and fish;” they feed hungry human beings and are part of nature.
If we deny that grace works with nature and instead say that it supercedes it, indeed replaces and destroys it, we have an analogous problem with miracles and can no longer assume a God who is not simply arbitrary in His will and design. One is free, I imagine, to believe in such a God, as is the result of nominalist thinking along the lines of William of Occam, which undoubtedly leads to occasionalism, a close partner.
But once we accept this, we say that things are so merely because God says they are, to the point where, if God commanded murder, if God commanded even idolotry and denial of God by humans, these would by that fact be the right things to do.
This is, indeed, the teaching of Islam, and the teaching of reformed (Calvinist) theology within Christianity. Things happen because of God’s will, but apart from this being in line with His nature as goodness itself. One may look to Plato’s Euthyphro to see an in-depth discussion of whether things are good because God says so or if God says so because they are good. The Christian answer, for centuries, has always been that it is both, and that it is a false dichotomy to ask the either/or question.
However, in those that fall into the camps of either emphasizing God’s sovereignty to the detriment of man’s freedom (John Calvin) or emphasizing man’s freedom to the detriment of God’s sovereignty (Jacobus Arminius), the old problem has returned. We need, instead, the clear picture that God’s goodness, His will, His love, and all of the features we apply to God are indeed one and simple in Him, who simply IS.
Why, then, do we struggle to understand the place of our free will and our works in salvation?
St. Thomas teaches us, in the most clear manner, the truth of Predestination and man’s cooperation through God’s grace:
Wherefore we must say otherwise that in predestination two things are to be considered–namely, the divine ordination; and its effect. As regards the former, in no possible way can predestination be furthered by the prayers of the saints. For it is not due to their prayers that anyone is predestined by God. As regards the latter, predestination is said to be helped by the prayers of the saints, and by other good works; because providence, of which predestination is a part, does not do away with secondary causes but so provides effects, that the order of secondary causes falls also under providence. So, as natural effects are provided by God in such a way that natural causes are directed to bring about those natural effects, without which those effects would not happen; so the salvation of a person is predestined by God in such a way, that whatever helps that person towards salvation falls under the order of predestination; whether it be one’s own prayers or those of another; or other good works, and such like, without which one would not attain to salvation. Whence, the predestined must strive after good works and prayer; because through these means predestination is most certainly fulfilled. For this reason it is said: “Labor more that by good works you may make sure your calling and election” (2 Peter 1:10).
“I have been crucified with Christ and I no longer live, but Christ lives in me. The life I live in the body, I live by faith in the Son of God, who loved me and gave himself for me.” It is this Christ “who worketh in you, both to will and to accomplish, according to his good will” and who will “render to every man according to his deeds: To them who by patient continuance in well doing seek for glory and honour and immortality, eternal life.” Certainly, it is by grace we are saved and “we are God’s workmanship, created in Christ Jesus to do good works, which God prepared in advance for us to do.”
But do not be fooled; these works are part of how we are judged unto salvation or damnation, when Christ “will sit on his glorious throne. All the nations will be gathered before him, and he will separate the people one from another as a shepherd separates the sheep from the goats. He will put the sheep on his right and the goats on his left.”
All these, both sheep and goats, are judged by what they did or did not do. It is by grace, a pure gift, that I may be saved, but I find no evidence that Christ will say, at the judgement, “come, you who were predestined by grace apart from works” but rather we know from the mouth of the King of Kings that we will hear one of two things:
‘Come, you who are blessed by my Father; take your inheritance, the kingdom prepared for you since the creation of the world. For I was hungry and you gave me something to eat, I was thirsty and you gave me something to drink, I was a stranger and you invited me in, I needed clothes and you clothed me, I was sick and you looked after me, I was in prison and you came to visit me.’
‘Depart from me, you who are cursed, into the eternal fire prepared for the devil and his angels. For I was hungry and you gave me nothing to eat, I was thirsty and you gave me nothing to drink, I was a stranger and you did not invite me in, I needed clothes and you did not clothe me, I was sick and in prison and you did not look after me.’