If there's a God and He's omnipotent, then all the old men living long perverted lives raping bombing and starving children are His fault. Cancer, his creation. A quarter of all pregnancies, which the Omnipotent One created, He aborts. He raises heartless hypocrites to prominence and starves hardworking people who worship Him honestly and live in Christ's example. If God exists and He's watching you now, he's laughing with cruelty at you.
Or... No, people get pregnant and some miscarry. Evil people get rich because they're ruthless and manipulative, and they can afford things that keep them alive a long time. Luck determines whether hard work pays off or doesn't. Cancer is caused by a virus or a gene, and science has found some treatments by trial and error. Planets spin in space, and some are swallowed up by black holes. Life evolves or it doesn't, and it takes millions of forms, and some of them think they're important.
The Spanish Inquisition used your excuse, if they tortured the wrong person to death, they'd go to Heaven. Heaven is just an excuse for cruelty here on Earth, and Grace and Forgiveness are the loophole the evil ones expect to use to get to Heaven themselves.
Whether or not you believe in Heaven or God, if you want to be a moral person you should start paying attention to how you help others in the Here and the Now.
Otherwise you're just abdicating your moral responsibilities by throwing it all to Big Sky Guy.
But just like Science, Goodness doesn't rely on Faith. You can just do it, even when it's hard, because you do have it in you. You're full of good and evil and neutral, just like the Universe, and you just have to choose.