God exists. Now, most of you are probably thinking, “Well, duh.” But not everyone does, perhaps like you. So, you are due, someday, to meet an infidel (perhaps yourself), and you may have to defend yourself, or even prove God to him or her. You could go down the easy route, saying the Bible tells us so. Not to knock you from that, but not everyone believes the Bible. (And proving the Bible is an article for a different day.)
So, what to do? Assuming your opponent is reasonable, and willing to listen, there is a clear, easy way to prove God: logic. It may not work every time (some people have skin too tough for reason), but even if it doesn’t, you will have at least shown you are a reasonable person.
One of the best arguments is the complexity and diversity of creation. You could refute evolution, pointing out the errors in the theory: the errors in the fossil record (Ninety of all discoveries are clams! The fossil record is not a perfect graph like the textbooks say! The Cambrian explosion (look that up)!), the deep complexity even the simplest bacterium displays (many scientists have been converted on that), the gene errors of evolution (aka structural homology and genes), the lack and ill-fitting of so-called “transitional forms”, the deep rifts in the argument of evolutionary speed, et cetera ad infinitum. Or you could point out the order in the universe, the symbiosis and the harmony, and then point to God as the Designer for this deep complexity. If your opponent has ears to hear, you can easily prove the creation argument.
But we can use even purer logic to prove the Divine Being. St. Thomas Aquinas, in the Summa Theologica, presented five arguments for the existence of God. We have already viewed one: the argument from design (in the above paragraph). Two very similar ones intrigued me: the argument from motion and the argument from efficient cause. The argument from motion says that everything is moved by another. So, we can form a great “movement” chain, linking action to action. But everything has to start somewhere, and St. Thomas puts it simply: God is the First Mover. Similarly, the efficient cause argument notes that nothing can cause itself. In the same form of the “mover argument”, something has to cause something, and that cause must be caused, and so must that cause, and that cause, et cetera. So, something must be the First Causer: God.
The other two arguments are the necessary being argument, and the gradation argument. The former states that all things can or cannot exist. But things cannot come from nothing (we know this from experience. Try to make a picture of yourself with no materials.). So, an eternal Being has to be around to create existing things: God. The second of the two notes the gradual complexity and goodness in creation: from inanimate stuff to us, complex rational beings. So there has to be something out there that is purely good and supremely complex. This person is God.
A final argument stems from Rene Descartes, the creator of the “cognito ergo sum” argument. Once he had (supposedly) proved his existence, he set out to prove God. The resulting argument has no theological error and is quite neat. It stems from the fact we all have an idea of perfection, but are not perfect (no amount of pride can change this). So, how can imperfect beings think of perfect things? Descartes realized a perfect being must have given us this ability, and concluded this perfect being is God. Plain and simple.
So, there are many ways to prove God to others. But don’t root all your belief in God in reason. As He Himself said, “Because thou hast seen me Thomas, thou hast believed: blessed are they that have not seen and have believed.” (John 20:29, Douay-Rheims)
Use logic to help your belief in God go beyond what your mind and eyes see. New belief comes from the soul and not the mind. Remember that.