Skip to main contentAccessibility feedback
Get Your 2025 Catholic Answers Calendar Today...Limited Copies Available

God Makes an Atheist Cease to Exist

What are some of the atheist's most compelling arguments against the existence of God? It turns out they were resolved, in God's favor, a long time ago.

Kevin Vost

“How can God be all-powerful and all-knowing? If he knows what he’s going to do tomorrow, then he doesn’t have the power to do something different.”

“Existence exists! Open your eyes and see the universe. This is your starting point. It makes no sense to ask where existence came from.”

“Who made God?”

Ah, back in the 1970s, when the world was young (or at least I was), these were heady questions and arguments indeed, proposed decades before by brilliant, daring atheists like novelist Ayn Rand and philosopher Bertrand Russell. Having gone through Catholic grade school and high school, I was never taught how to address them (or if I was, I was not paying attention that day).

A famous saying goes, “A little philosophy leads to atheism,” and that is exactly where it led me for a quarter of a century, from my late teens until my early forties. I had wished during those years that I could still believe in God, but I felt in all honesty that I could not, because I had been convinced by arguments like those above—that the idea of God was self-contradictory, and that God was unnecessary or insufficient to explain our existence.

Thanks be to the God I did not believe in for so long, I was eventually led to the answers to those dilemmas and thereby back to him. A series of events, starting with viewing a video course on natural law that happened to be taught by a Catholic priest, led me to read St. Thomas Aquinas for the first time. All it took was a little bit of Thomas’s philosophy to dissolve my atheism, and not a molecule has reconstituted itself for almost two decades now. The answers to modern atheists’ questions had lain buried within the treasures of the writings of our Catholic Church Doctors for many hundreds of years, and I had had not a clue!

When I read Aquinas, I found rich, satisfying answers to each of the atheists’ questions that drew me away from God. I will highlight the three that started this article.

1. God has no yesterday, today, or tomorrow

Regarding the supposed contradiction between God being omniscient (all-knowing) and omnipotent (all-powerful), it sure does present a bit of a conundrum if we try to make God in our own image, rather than realizing that the true case is the other way around. Thomas makes clear that God is not merely some superior being, but Being itself, with a capital B—the infinite origin and sustainer of all that exists. He is not like a super-sized Superman with powers beyond normal humans, impervious even to kryptonite; rather, as the Creator of all caused things, he surpasses all created things that were made and exist in time, with yesterdays, todays, and tomorrows.

God himself, being “pure act,” being eternally perfectly actualized, per Thomas Aquinas, “his glance is carried from eternity over all things as they are in the potentiality.” God exists in an eternal now without the yesterdays, todays, or tomorrows we experience in our own existence limited by time. Thomas says that future things are contingent to us, but “certain to God alone, whose understanding is in eternity above time,” “just as he who goes along the road, does not see those who come after him; whereas he who sees the whole road from a height, sees at once all traveling along the way” (from Summa Theologiae, I, Q. 14, a. 13).

2. God is the only necessary being

“Existence exists!” No argument there, but can we satisfactorily answer the question of why all that we see exists with “it just does,” with no further questioning? What thing in the universe gave itself its own existence?

Thomas argues in his “third way” to God that we find in nature things that are possible to be or not to be—things that come to be but pass away. If everything in the universe is possible not to be (that is, contingent, being dependent on something else), then at one time, there could have been no existing thing. If that were true, there would be nothing now, because something that does not exist cannot give itself its own existence. There must therefore be some being that not merely possibly exists, but necessarily exists, having received its existence from no other thing, but which causes other things to exist. We call this necessary being God.

3. God is the only uncaused cause

To ask “who made God?”—a question Bertrand Russell said led to his atheism as a child—begs the question, assuming from the start that God was made. But the God attained through reason and revealed in Scripture is the only uncaused cause, the Creator, and no created thing.

Does “necessary being” ring any bells? Yes, every caused thing must have a cause, but God, the uncaused cause, is the cause of all things and the effect of no other cause. As Thomas explains elsewhere, God is the only being whose essence (what he is) and existence (that he is) are one. He is his own existence and the cause and sustainer of all that exists.

Perhaps the spinach-scarfing cartoon character Popeye’s most famous saying is “I yam what I yam.” Truly, every one of us can say the same, that we are indeed what we are. Only God, though, can drop those last three words and declare, merely, “I AM.” Indeed, he told Moses that is his name! (Exod. 3:14). Here we have, expressed in two words by dusty ancient desert-dwellers, God’s revelation that 1) God is eternal. He tells us he is, not that he was or will be; 2) God is necessary being, or existence itself; and 3) God is the cause and Creator of all things that exist.

In St. Thomas Aquinas, I found rational arguments grounded in the evidence of our senses that lead to the fact of God’s existence; his eternity, necessity, and uncaused causal power; and so much more. It certainly helped that the great “I AM” revealed to Moses that he is “the God of Abraham, the God of Isaac, and the God of Jacob” as well (Exod. 3:15). Later, I would recall that Jesus Christ, “the Word” of God, through whom all things were made (John 1:1-3), would also reveal to us that “before Abraham was, I am” (8:58).

So I exaggerated just a bit. God did not make this atheist cease to exist; he merely made my atheism disappear. He merely added a space, changing atheist to a theist. He led me to Thomas and his nearly inexhaustible insights regarding just what and who God is. I became so awed and enthralled that I just could not help trying to pass some of Thomas’s wisdom along to people in our day—to those who want to know if God is really there, and to those who want to know and love him more deeply.


Kevin Vost’s new book What Is God?, available from Catholic Answers Press, takes on these questions and many more. Buy the book now at our shop.

Did you like this content? Please help keep us ad-free
Enjoying this content?  Please support our mission!Donatewww.catholic.com/support-us