go with gut

That sounds nice, and all, but how do you know it is correct?

brings happiness and good life

Which is what Christianity does, yes?

Stalin, mao, and pol pot were Athiesm believers. If God were "fake", morality is just made up and theres no Afterlife. So they followed the logical conclusions of athiesm and were consistent in their worldview. So clearly, athiesm brings devastation and a terrible life to people.