Because religion is laughable

Scientific Proof God Exists

 Funny Scientific Proof God Exists Funny Joke Tumbleweed Gif

Seriously,  before we get to the question of God's existence, we need some definitions; because for the question to even make sense, the individual terms need to make sense.  We cannot ask, "Is proposition P true, if P is in itself a contradiction."  Which is why we are not reasonably allowed to ask silly questions like: "Can God make a rock so big he can't lift it?"

So what of the term "God"?

Even if we pick just one of the many definitions proposed by religion, e.g. the Christian one, we still have a being that: exists apart from existence as we know it; is both one and three beings; predestines (or preknows) what we are going to do, yet alleges we have free will; seems to be at odds with himself; and demonstrates inconsistent, psychotic behaviour.  In other words, a very paradoxical being indeed.

Christians like to refer to this paradox as a mystery, but that's just wordplay.  I don't think the question "Does God exist?" can be sensibly asked.