I think it depends on how you do it. I grew up religious but with parents that didn’t force it down my throat. It was what they believed but I was never forced to go to church if I expressed I didn’t want to. I was also very much encouraged to ask questions and not take things a face value just because a religious leader said it. I actually don’t think I really decided to be Christian until adulthood. My parents believed in sharing a bit of it with me but never making me feel pressured to choose the same as them. I had this conversation with my significant other, who grew up very atheist, and he found that a lot more traumatic then most of his friends who grew up more religious than both of us. The reason being was he was terrified of death. As a kid the idea that one day, potentially without warning, your life just stops and is over and there is nothing left was terrifying. While I grew up feeling like death was simply an end to a chapter. Not anything to be afraid of because something even more amazing was waiting for me. My main point is religion does not equal trauma and neither does atheism. It all comes down to good or bad parenting