Sigh…I said I wouldn't do it…I staved off the temptation to continue discussion but you know what, I have the urge to drop my two cents on some things here.
I know this is semantics but do bear in mind that this is just something I feel needs to be pointed out for the sake of keeping proper definitions.
In science, the term 'theory' does not refer to some random guess or idea some guy had while he was in his shower. A theory in science is an explanation for a phenomenon or set of phenomenon supported and substantiated by a wide body of evidence and observations. Examples include Germ Theory, Cell Theory, atomic theory, and Transition State Theory.
By saying 'only theories exist', it kinda downplays what a theory is in science. Now, granted by definition, a theory can never be proven correct. It can only be disproven or supported. But, as further experimentation is done, if evidence comes along to refute or disprove a scientific theory, scientists are more than willing to either revise a current theory so that said evidence/observation can be explained or scrap the current theory completely and work again from scratch to create a better definition that encompasses all of the evidence.
Just wanted to get this definition out of the way.
Your first two paragraphs are basically Pascal's Wager in a nutshell. Now, you obviously brought up one of the biggest issues with Pascal's Wager being that over the course of history, many different religions have been developed by humanity, each with its constituents believing that they follow the right religion. But the thing is you are dismissing it straight off saying that it's still better to take the risk. Here's the problem. You believe in the wrong god and most religions with some sort of judgement after life will say that you will be punished by god(s). What you're saying is to take a gamble on one of the many religions and believe that you will win despite the high probability that you may fail.
Going off from the probability standpoint, there are an incredible amount of denominations of Christianity for example, each with its own interpretation of the Bible, along with hundreds of different translations of the Bible, each with various details differing. A Catholic and an Evangelical do not believe the same thing. A Pentacostal and a Calvinist will not believe the same thing. A Jehova's Witness and a Russian Orthodox…ist(? not sure how to denote that) do not believe in the same thing. How does one know that they have the right interpretation? Now, I'm guessing that the answer is faith but at that point, we reach an impasse.
Last point, if there is a God and he is as described by some Christians, I highly doubt that He will take kindly to people who believe out of fear of hell. It lacks a sense of sincerity, yet that is exactly what the wager you have proposed is. Once you brought up that "the hard part is actually believing," you stopped attempting to convince us with rationality and objectivity. It became a discussion of how you believe something and why you do so. Now, I am not going to attempt to break that apart as your beliefs are your own and I frankly have better things to do than being a dick to someone about their religious beliefs. But my point is this. Everything before that line was an appeal to fear of eternity. Not exactly rational if I say so myself.
Now, then, let me clarify my own view. My view is that I have no reason to believe in the existence of a god, like I said before. However, I believe that if a god or gods exist, then they do not reflect how people have portrayed them through religion.