Is Belief in God Rational?

Image Credit: After the Big Bang? used by permission. © Marjan Smeijsters AKA ‘De Rode Olifant’

The question of the existence of God is an important one to ask. There are many different arguments for or against the existence of God, but not all of them can be true.

Some think that belief in God is irrational. Others think that He exists but that it cannot be proven; thus they just believe or take the proverbial leap of faith.

Belief in God’s existence, however, is neither irrational nor blind. There are good reasons and rational arguments to believe in His existence. In this post, I will briefly explain the argument from creation as well as the moral argument in regards to the existence of God.

The Creation Argument

The argument from creation states that all finite things have a cause. Something cannot come from nothing.

It is now fairly certain that the universe is finite from evidence such as the Big Bang Theory (recently strengthened further by the discovery of gravitational waves) and the second law of thermodynamics, which states that all things in the universe are running out of energy.

If the universe is finite, then it follows that it had a cause. What or who can cause space, time and matter, all of which started at the point of the Big Bang?

The cause had to be intelligent due to the amount of design observed in all of creation. The cause had to be infinite since time began at the point of the Big Bang. The cause also had to be immaterial since matter began at that point as well. All of these requirements point to the cause being the infinite and omniscient mind of God.

On a more philosophical stance, the argument from creation points to an initial cause of our finite universe since logically there cannot be an unending series of past causes. Geisler and Brooks say,

If the past is infinite…then we could never have passed through time to get to today. If the past is an infinite series of moments, and right now is where that series stops, then we would have passed through an infinite series and that is impossible

In other words, moments or time had to have a beginning. They are finite. Finite things must have a cause. The cause of time, we call God.

The Moral Argument

While many values are subjective, and cultures differ on what they hold dear, there are certain things that all people believe to be wrong, such as murder, rape, theft and lying. If one were only able to observe humanity and describe behaviour, however, these morals would not be evident. This is because morals do not describe behaviour; they prescribe it. Morals tell us what we ought to do whether we behave that way or not.

Since one cannot gather an understanding of morals from observing humanity or creation, where do they come from?

They have to come from outside humanity and creation. To use other words, morals transcend humanity and the universe. Are they there by chance? If that was the case, we would be able to ignore morals for there would be no authority behind them, and we could do as we pleased. Nor would morals-by-chance explain the feelings of obligation to do something we ought to do, or the feelings of guilt when we know we have done something wrong.

Since these universal morals carry this seeming weight of obligation/guilt, they must come from a source of authority. This implies a lawgiver. A lawgiver implies intelligence. And again, we are back to a transcendent, intelligent source – God.

As Koukl says,

Moral laws suggest a moral law-giver, one who communicates his desires through his laws. He expects his imperatives to be obeyed.

In summary, we have good reasons from science and philosophy pointing to an initial cause of creation that is intelligent, immaterial and infinite – God. We also see moral laws across humanity that point to a transcendent lawgiver.

Believing in the existence of God is neither irrational nor blind.