Why is there no proof of God’s existence? If you ask a Christian this question, you get a barrage of “proof” that after a little digging, turns out to be nothing but faith.

However, some of the Christians I have met (I even entertained this idea at one point in time as being the reason I couldn’t find proof of God’s existence) claim that there is no proof of God because God is in principle, undetectable.

The idea goes something like this… God transcends time, space, and even the universe itself. Our science instruments are limited to the universe, so that’s why we can’t detect God. We will never be able to detect God because our instruments will always be limited to the natural things that are lurking about in the universe. Since God can exist and be undetectable, we must take it on faith that he does exist.

Something that can in principle never be detected, is by definition, nonexistent and I’ll explain why in the next few paragraphs.

We detect things by the way they affect other things. For example, we directly detect the moon because of the way it reflects particles of light. We also indirectly detect the moon by the gravitational force that it exerts on the Earth and its contents.

The only way that something cannot in principle be detected even indirectly is if it has no effect on anything else in the universe. In other words, it cannot have mass because then it would exert a gravitational force which could in principle be detected with gravity gradiometers. It cannot have any sort of electrical charge because then it could in principle be detected with a variety of electromagnetic detectors. For any other property of something that exists, there could in principle, be designed a detector which detects that property, otherwise the property isn’t real. In other words, the only way that something cannot in principle be detected even indirectly is if it has no real properties.

And let’s not forget statistical analysis. Even if something real could not be detected by scientific tools, if it affects real objects or events, then its influence could, in theory, be statistically calculated using our knowledge of the affected objects or events and our knowledge of how the universe works.

In conclusion, the idea that something could be said to exist and at the same time be undetectable in principle, doesn’t make sense. It is a contradiction. On the other hand, if you decide to drop the idea that God is in principle undetectable while maintaining that he does exist, then the burden of proof is on you. If you claim the existence of something which has heretofore not been verified, then it is your burden to propose a method of detection that would reasonably prove its existence.