Certainly American statesmen who grew up in that tradition have been far better stewards of liberty than have been Hitler, Stalin, and Mao.
But personally, I have never experienced even the faintest hint of anything supernatural in my 50+ years.
So even though the Christian religion has been a beneficial thing on balance, I find no indications that it is true.
That you believe that Christianity has been beneficial, means you have an idea of what things should be rather than what they are. This is the core of the Christian concept of the Fall of Man. Go with that, expand on it, dig into it. C.S. Lewis’s “Mere Christianity” and “The Problem of Pain” go into great detail on that conflict.
Spot on.
What “proof” would you require to conlude truth is or not? and what would be your measure either way?