I was raised Christian. It took years to figure out my relationship with the God that had been taught to me. Over the years, I examined the reasons I was told to believe. There are many things I could say about why I now don't worship, believe, or even have interest in God, but this quote pretty much sums up the basics.
"Live a good life. If there are gods and they are just, then they will not care how devout you have been, but will welcome you based on the virtues you have lived by. If there are gods, but unjust, then you should not want to worship them. If there are no gods, then you will be gone, but will have lived a noble life that will live on in the memories of your loved ones." –Marcus Aurelius