Does God Exist?

Good question.

Everyone struggles with this question at some point during their lives, often more than once. The short answer is "yes."

The long answer describes how we can prove it by reasoning our way through the problem. This was done most brilliantly by St. Thomas Aquinas, a Catholic monk most famous for writing a summary of the faith, the Summa Theologica, written between 1265-1274 A.D. The full text of this towering intellectual achievement is available online, but it's huge; I prefer the high-level overview of the Tour of the Summa, by Msgr. Paul Glenn. The following arguments are from this summary.

There are five main ways of reasoning out the truth that God exists:

1. First Mover

The first way is by considering motion in the world. Where there is motion, there is a mover, and ultimately a first mover, itself unmoved. This is God.

2. First Cause

The second way is by considering the chains of effecting causes that exist in the world. Things here are produced by their causes; these causes in turn were produced by their causes, and so on. Ultimately, there must be a first cause which is itself uncaused. This is God.

When people ask "Who created God?", the answer is: "Nobody. God is the First Cause. There is nothing outside of God.

3. Necessary Being

The third way is by considering the contingency of things in the world. Contingent things do not have to exist; they are non-necessary; they come into existence, and undergo change, and pass away. Now, contingent things demaind as their ultimate explanation a noncontingent being, a necessary being. This is God.

In other words, every being must be either necessary or contingent. Since not every being can be contingent, it follows that there must be a necessary being upon which all things depend. This being is God.

4. Absolute Perfection

The foutrh way is by considering the scale of perfection manifest in the world. Things are more or less good, more or less noble, and so on. Now, where there is good and better and still better, there must at last be a best which is the source and measure of goodness all along the line. And where there is noble and nobles and still more noble, there must ultimately be a noblest which is the standard by which all lesser degrees of nobleness can be known and given their rating. In a word, where there are degrees of perfection, there must ultimately be absolute perfection. This is God.

5. First and Absolute Ingelligence

The fifth way is by considering the order and government seen in this world. Things act in a definite way and were menifestly designed to act so; through their nature (that is, their active or operating essence) they are governed in their activities. Thus there are design and government in the world. Therefore there are ultimately a first designer and first governor. And since both design and government involve intelligence, there must be a governor and designer who is the first an absolute intelligence. This is God.

Faith

I was born and raised Catholic but lost my faith, like so many others, through pride of youth. Becoming a Catholic convert in my old age has been a great intellectual exercise. These five arguments by Aquinas provide much to think about, and in the process I have come to realize that faith is not a feeling. Faith is a decision based on reason. I wish you well with your own quest for meaning, and I hope these arguments help you on your own journey.