This is a point that I argue with all the time but it goes ignored.
I find it interesting and contradictory that a theist has the ability to just decide which gods do or do not exist. How is it that you can determine which gods do no exist and which ones do?
It is just a matter of picking and choosing as far as I can tell. All that matters is that you pick one and then that one will be correct. You don't need any evidence, you don't even need to reason it out with anyone. It is absolutely correct, because you chose it to be.
The belief that a God exists is reinforced by the evidence. (I will concede that religion may be a tendency built into humans--but that doesn't necessarily dictate that all religions are false.) Meanwhile, we can't conclude that there is more than one omnipotent, omniscient being; I don't see any reason to conclude this. And, there would need to be some distinction between them--meaning that one would be different from the other, meaning that this one would lack something the other possessed, thus making it not omnipotent/omniscient.
Also, I think you may have misunderstood my statement if you think what I said before is something you argue all the time.
If the christian argument is that god is the author of all things, then it would stand to reason that evidence would be left within all things that that being the case, however; the evidence is to the contrary of that statement.
For example. We do not see five thousand interpretations of various forms of math. We don't have math teachers debating geometry. There might be some high levels of math that are debated but they also fall into the realm of un-proofs and that is why they are so debated.
Now if there was some validity to religion or specifically Christianity there should be a consensus to it's truth or proofs. However; there is not a single consensus with the system. You would think there would be at least one consensus but there is not even a single agreement at all. This to me is a red flag.
First, most religions have some element of the truth that Christians profess. Many, if not most, religions deal with some sort of higher being--which God is. I'd say that's a mark that God left. Now, why are there so many different religions? I would put forth that it's because God has 1) given humans free will to believe what they choose, and 2) given those who believe in him a field in which to live for him (going on Christian missions, for example.) But we are once more, we are debating God's reasoning behind doing things. This doesn't satisfy anything (except philosophical/theological curiosity), since most of God's reasoning we will probably never know.
Second, your analogy works only up to a certain point. I believe that math is fact and that God is just as much of a fact. But there is another factor present in the case of belief in God that is absent in the case of belief in math. If you disbelieve that the Pythagorean theorem is true, and I prove conclusively to you that it is true, that's not going to have any bearing on what you do with your desires, your urges, and your choices throughout your life.
However, if I prove to you (let's save the question of whether or not I can prove this for another thread) beyond a shadow of a doubt that God exists and that he created everything that exists in the universe, that will potentially have some bearing on the way you live your life. In atheism, there is (technically) no moral accountability. However, if it's proven reasonably to you that God created people and then you observe that most if not all people possess some sort of moral code within, it's not unreasonable to conclude that God placed that code there deliberately. The implication, then, would be that a person would have an obligation to obey the code. A pre-established unwillingness to do so may conflict with an acceptance of the evidence for Christianity provided.
If there is a god, and that got is the author of all things, you would find it's signature on all things. Since there is no consistent authorship then it stands to reason that there is no single author, ie. god.
I've sort of already responded to this. I disagree with your premise and your conclusion. I'd say God's mark can be found on most, if not all, world religions--and even if this wasn't so, it wouldn't be a very good reason to disbelieve the existence of God.