I have determined a scientific experiment that if performed correctly would conclusively answer the question of the existence of God (Capital G). Be warned, this isn't making a volcano out of baking soda or lighting your farts on fire or any of the other fun and fantastic scientific activities of your youth. All you need is a lottery ticket, a Sharpie, and a murder most foul.
Step One: Buy a lottery ticket with a truly biblical payoff. Something that would make you richer than God, or the very least half as rich as a decent sized Catholic Diocese. $100 million should suffic.
Step Two: Find an innocent to sacrifice. A small child is safest, but if you are squeamish choose someone older just make sure they in no way deserve an untimely death. In fact if you want to be really thorough statistically speaking, make it a small group Safer yet round it up to a bus load.
Step Three. Murder most foul.
Step Four. Write the number of the lottery ticket onto one or more of the bodies. Make it legible and maybe add the word "Clue" with a an arrow just so the police don't miss it.
Step Five: Wait for the lottery draw, where the jackpot is cosmic truth.
Now I have made a few assumptions here. You didn't leave any other evidence that would link you to the crime. You wore gloves. You didn't drop your wallet at the scene. You didn't leave any witnesses. We have all seen enough crime drama on TV to know how to commit murder without getting caught. The real key is, you picked your victim at random and you have no history of violent crime.
So if you did manage to pull it off and the police have no evidence linking you to this heinous crime but that lottery number, we are in a position to get scientific. You kept the ticket right?
I need to clarify what some might call my confirmation bias, but I refer to as calling bullshit on circular logic. That is to say, that if there is a loving and attentive God watching over his precious flock his reaction would be predictable. If he is the smiting, prayer answering, touching of the faithful entity he has been characterized as, he will not be able to resist the temptation to make that lottery number hit. He has to. The irony is too sweet to pass up for a deity worth his salt. If that number hits, you can't claim the enormous payday without also taking the rap for murder most foul. You'd be fucked. And God loves fucking people, just ask a priest.
So there you have it. If you really have to know, you have the methodology. Go prove it to yourself, and if you are truly generous the world. There is no reason anyone need wonder or suffer crisis of faith ever again, the fruit of knowledge is within your grasp.
The other option is to just take it as a matter of course that the very idea of an all powerful creator watching over his children is simply a desperate attempt to placate your id from the sting of realizing the grossly aggrandizing misconceptions you formed about your mother when you were an infant. She was warmth, security, and sustenance. A world filling presence, all powerful and yet solely focused on answering your cries with a soothing voice. It must have been a real piss off to realize she was just a dolt that forgot to take her pill, and were just another product of the biological imperative.
So really, you can either take my word for it and carry as if there is no God, or .. you know... murder most foul.