Back in 2013, at the height of the so-called “New Atheism,” I realized that many young people were being drawn into this movement, swayed by poor arguments and heated rhetoric, in particular through the internet. That group included a lot of young Catholics who were never taught rational reasons to believe in God and had thus come to believe that religious belief was little more than superstition.
In response, I created a new website, StrangeNotions.com, a place where serious-minded Catholics and atheists could come together to charitably discuss the important questions of life, from the existence of God to morality, science, philosophy, and more. We launched with over thirty contributors, including some of the brightest thinkers, writers, and artists in the English-speaking world. With 100,000 conversations under our belt, I have now interacted with thousands of atheists and have learned how they think, their major obstacles, and their points of resistance.
Based on this experience, I would like to share some effective tips and tactics to use when speaking with the atheists in your own life, whether they be friends or family members.
Tip #1: Respect Their Intelligence
Some Christians think all atheists are ridiculous, so they openly mock or belittle those who question God. You should never make that mistake. Most atheists I have met are smart, sincere, and good-hearted. And even if they are not, treat them as if they are. Don’t talk down to them or speak condescendingly, the way you might to a child. Treat them with respect and acknowledge their intelligence. When you do, they’ll be much more likely to listen to what you have to say. My friend, Catholic writer and speaker Jennifer Fulwiler, even recommends using this tactic as a clandestine spur to belief, saying something like, “Oh, come on, you’re too smart to be an atheist! I know you can see through those bad arguments…”
Tip #2: Find Common Ground
When you talk with a religious skeptic, you will likely disagree about God and religion. Do not start there. Instead, focus on areas of agreement. For instance, perhaps you both appreciate the value of science or critical thinking. Start with that. Hopefully you both agree that we should follow the evidence wherever it leads, even if it requires us to reject some cherished beliefs and to change our minds. Begin your conversation on a good foot and find common ground. Then, once you have established some rapport, you will be ready to move on to points of disagreement.
Tip #3: Ask Good Questions
Instead of trying to present your views aggressively to your atheist friend, first ask them what they believe. This tact will accomplish two results simultaneously. First, you will understand where they are coming from, so you are not responding to a straw man version of their beliefs; second, you will force them to clarify exactly what they believe, which can lead them to detect holes in their view that will cause them to question their atheist beliefs.
Along these lines, there are two questions I love to raise with an atheist. First, I like to ask, “Which argument for God do you find strongest, and why does it fail?” Or to ask it another way, “What’s the best reason to believe in God, and why does it not convince you?” This angle puts them on the spot—not in a bad way but in a way that causes them to reflect on whether they have actually considered the God question fairly and thoroughly.
In my experience, few atheists have actually read books defending God or have studied the issue at length. Therefore, they’ll usually respond by referencing a relatively poor argument or reason, one that you and I could probably quickly reject. The most common answer they give is, “Well, the world is so complex that many people rely on God to explain things like biological complexity, things that science can’t currently explain. But science is increasingly closing all of those gaps of knowledge, pushing God to the margins.” This is what is known as a “God of the gaps” argument, and it is so weak an argument that no serious Christian could rely on it. So, when your atheist friend suggests that is the strongest reason for belief that he can think of, you can kindly reply, saying, “Oh? That’s the best reason you’ve encountered? I can think of several better reasons to believe in God than that. For example…” and then explain another more powerful argument, like the one further down in this essay.
Another strategy is to ask, “What would it take for you to believe in God?” This question will help reveal whether the person is genuinely open to believing in God or whether he is closed-minded, demanding such an impossibly high standard of evidence. When I ask atheists this question, I sometimes hear, “Well, I guess I’d believe in God if he appeared right in front of me and told me he existed, or if he wrote something in the stars such as ‘My name is God and I exist.’” The problem with answers like this, as you can point out, is that such displays might be surprising and extraordinary, but even if they occurred, a skeptic could still find some way to explain them away. For example, maybe the skeptic was just hallucinating when he encountered someone claiming to be God, or maybe what looked like writing in the stars was actually a light projection from some prankster or government experiment. Experiences like these can always be explained away through natural causes. So, if these are the sort of answers you get, push back a little and suggest we really need a higher and more convincing reason to believe in God, something like a philosophical argument. And then again, present such an argument.
Evidence for God?
Someone once asked the twentieth-century atheist philosopher Bertrand Russell what he would say if he found himself standing before God on judgment day and God asked him, “Why didn’t you believe in me?” Russell replied, “I would say, ‘Not enough evidence, God! Not enough evidence!’” If you hang around skeptics or atheists long enough, you will hear the same response. People are open to believing in God, if only there were enough evidence!
When your friend or family member asserts that there is no evidence for God, do not panic. Believe it or not, they have already taken an important first step. When someone wants proof or evidence before they accept a belief, that’s commendable. It means they are not willing to believe something without support.
We should, however, clarify: what do they mean by evidence? Oftentimes what people really want is scientific evidence. In the realm of science, evidence refers to data you can see, hear, taste, touch, or smell—things that directly confirm or undermine a hypothesis. And in the context of science, such evidence has led to remarkable results. Just look at the advancements in technology and medicine.
However, scientific evidence isn’t the only type of evidence. Many truths that exist we cannot prove through physical evidence. For instance, we don’t have physical evidence that life is meaningful or that murder is wrong. Of course, we understand these statements to be true, but not because we have found physical evidence to support them. We believe these truths on the basis of another sort of evidence.
The same holds for the existence of God. Whether you believe God exists or not, He is, by definition, immaterial and transcendent. He is immaterial because He is not composed of physical matter, not made of material stuff like you and me. And God is transcendent because He exists beyond space and time. Thus, when we’re searching for God, we do not expect to find direct, physical, scientific evidence for His existence within space and time. This fact is important: it is not just that we have not yet found such evidence, though it may exist, it is that such evidence is impossible, even in principle. We are not going to find one of God’s hairs, or discover his footprint, or run a scientific experiment to see if he exists.
Does that mean it is impossible to demonstrate that God exists? No. It simply means that science is not the right means, just as a metal detector is not the right tool to find a wooden cup. We need other tools when exploring nonscientific questions.
What other tools are there, besides science? One such tool is philosophy. Philosophy is concerned with life’s most important issues, from morality to meaning to God. Philosophy allows us to probe realities that can’t be detected through our senses; thus, philosophy provides an excellent method to explore evidence for the existence of God.
Philosophy typically offers evidence in the form of arguments. In fact, thinkers have identified no fewer than twenty arguments for God, arguments that range from the clear and simple to the extremely complex. Some of these arguments appeal to the universe or history, others to the existence of reason and beauty.
We can approach the God question from many angles, and there is no one best way. However, in this short essay, we are going to look at one of the arguments that I find to be the strongest.
A Strong Argument for God
Before we begin, I want to note that if terms like arguments or evidence disconcert you, you might instead consider these arguments as clues that converge and point to a common conclusion, much the way road signs guide you to a specific destination. A sign doesn’t prove that the destination exists, but it does point the way. These arguments are signposts to God. So, let us look at one signpost that in my opinion, presents perhaps the simplest yet most powerful argument for God’s existence.
The Kalam argument dates back to the Middle Ages but has been made popular today by William Lane Craig, an evangelical Christian philosopher. The argument is very simple; in fact, it is probably the easiest of all the arguments to memorize, having two premises and one conclusion:
Premise 1: Everything that begins to exist has a cause.
Premise 2: The universe began to exist.
Conclusion: The universe has a cause.
If you can memorize these three simple statements, you will be well equipped when dialoguing with a skeptic.
Let us unpack each of these three statements.
The First Premise. This statement says everything that begins to exist has a cause. It’s very important that we get this right. Some atheists try to refute the Kalam argument by responding, “Ah! Well, if everything that exists has a cause, and God exists, then what caused God?” But the premise does not claim, “Everything that exists has a cause.” It says, “Everything that begins to exist has a cause.” Since God, by definition, and whether you believe in Him or not, is eternal and never began to exist, this first premise does not apply to Him. Therefore, the rhetorical question “What caused God?” is like asking, “To whom is the bachelor married?” or “What caused the uncaused being?” Regardless of whether bachelors or uncaused beings exist, these questions do not make sense. They are literally nonsense because they confuse the meaning of terms.
Now that we have cleared away that misunderstanding, let us turn back to the first premise. Is it true? Does everything that begins to exist have a cause? For most people, the answer is yes; it is common sense. Almost nobody denies it. The statement simply means that nothing just springs into existence, randomly and without a cause. For if things did come into being this way, then our world would be a wild spree of things apparently popping into existence like sleight of hand magic. Only it would be worse, since with sleight of hand you at least have a magician who pulls rabbits out of a hat. However, in a world that violates this first premise, rabbits would pop in and out of being even without magicians or hats. Few sane people believe the world works this way. So, through experience and reflection most people agree that everything that begins to exist has a cause.
The Second Premise. This premise says that the universe began to exist. This claim is slightly more controversial than the first one. In fact, no less a thinker than St. Thomas Aquinas says that the truth that the world had a beginning of its duration is only conclusively known by faith and not by reason. Nonetheless, a host of the greatest minds from antiquity to the present, including St. Bonaventure in the Middle Ages and William Lane Craig today, offer arguments that purport to defend this truth. An example of one of these arguments, one which St. Bonaventure includes in his paradoxes of the infinite, goes as follows: If the world has always existed, then there would be an infinite number of past days. However, if there were an infinite number of past days, we never would have been able to arrive at the present day because an infinite series, by definition, cannot be traversed. Since we have arrived at today, it follows that there must have been a beginning of time.
Modern physics also seems to give weight to this position. Despite cyclic cosmological models advanced by some physicists in recent years, since the advent of the big bang theory in the twentieth century, the scientific consensus is that the universe did have a beginning roughly fourteen billion years ago. Alexander Vilenkin, a leading non-Christian cosmologist, was invited to speak at a colloquium for Stephen Hawking’s seventieth birthday. There, in front of the greatest scientists in the world, Vilenkin said, “All the evidence we have says that the universe had a beginning.” It is rare for scientists to speak with this measure of conclusiveness, but Vilenkin stated his opinion that it is not just that some of the evidence points to a beginning of the universe, or even the majority of evidence, but that all of the evidence points that way today.
The Conclusion of the Argument. The two premises are widely accepted today: everything that begins to exist has a cause, and the universe began to exist. If that is the case, then the third statement, the conclusion of the argument, logically follows. We cannot avoid the fact that if everything that begins to exist has a cause, and the universe began to exist, then the universe must have had a cause.
This logical conclusion leads us to wonder: if the universe had a cause, what is that cause? The cause certainly could not have been anything within the universe or even the universe itself, since things can’t cause themselves to come into existence. This idea defies logic. It would be like saying your arm caused you to come into existence, or that you yourself are the cause of your own existence. Neither statement could be true, for since before you existed, there was no arm and there was no you!
Thus, the cause of the universe must be something beyond the universe, something beyond all matter, energy, space, and time. In other words, it must be transcendent (beyond the universe), it must be immaterial (beyond matter and space), it must be eternal (beyond time), and if it has created something so massively complex as the universe, it must be tremendously powerful and intelligent. Well, a transcendent, immaterial, eternal, supremely powerful, and intelligent cause of the universe—what does that sound like to you? As Thomas Aquinas pithily puts it, “This is what most people mean by ‘God.’”
Now, this philosophical proof for God is fairly abstract. It doesn’t generate the warm, personal faith you might receive in prayer. And it doesn’t prove the fullness of God, especially those facts we know only because God has revealed them to us, such as that God is love or is a Trinity of persons.
However, the Kalam argument does give us a sign pointing in the right direction. Although not everyone will accept it, the Kalam argument is a rationally well-constructed and impressive argument that will be difficult for most atheists to reject. So, commit right now to memorizing these three simple statements:
Everything that begins to exist has a cause.
The universe began to exist.
The universe has a cause.
If you can memorize and recall these statements, you will have a powerful argument for God, and always be at the ready whenever someone challenges your faith. (In my new book, What to Say and How to Say It: Discuss Your Catholic Faith with Clarity and Confidence, I cover several other simple arguments for God.)
In the end, we should not let our atheist friends and family members intimidate us or make us feel anxious about defending our beliefs. Be confident in the fact that there are many good arguments for God. It is our job to share them.
About the Author

Brandon Vogt is a bestselling author and speaker who serves as content director for Bishop Robert Barron’s Word on Fire Catholic Ministries. He is the founder of StrangeNotions.com, a website of dialogue between Catholics and atheists. Vogt was named one of the “Top 30 Catholics under 30” by FOCUS. He is the author of seven books, including RETURN: How to Draw Your Child Back to the Church and The Church and New Media. Why I Am Catholic (and You Should Be Too) won first place in the 2018 Catholic Press Association book awards for popular presentation of the faith. His work has been featured by media outlets, including NPR, Fox News, CBS, EWTN, Vatican Radio, Our Sunday Visitor, National Review, and Christianity Today. He is a regular guest on Catholic radio and speaks to a variety of audiences about evangelization, new media, Catholic social teaching, and spirituality.