I'm 22 years old for fucks sake!

Anyone who's an atheist or agnostic knows how difficult it can be to let the people around you know it and then to go further and actually talk about it can feel like a nightmare. At least it does to me. I've gotten reactions that range from disgust to saying like "You'll think about things differently when you're older". Why do I have to feel like I'm walking on eggshells around them. I feel as though they are blindly believing in something for which they know nothing about. To me this is delusional . I'm not arrogant or think I'm in anyway better than anyone else but I just don't see how being religious ( believing in a supernatural creater that no one has ever seen) is beneficial mentally, but for some reason I'm the child. And I know some people will read this and think wow how arrogant and close minded, but I'm not wrong in saying that the man who finds Jesus in his cereal or talks to him in his head should be in a padded room right?