Do we need to have a religion? Does mankind need religion in general?

I keep asking myself and frankly so far I do not have a good answer. All sorts of religions, honestly, sound very childish to me (no offence meant) and it is really weird to believe that some people actually tie their purpose to something as impalpable as religion. To me it feels like a club, either you are part of it or you are not. I mean who is anyone to say the guy who is Hindu or Buddhist is wrong and the Christians or Catholics are right. There are so many beliefs, so many symbols, so many rituals. In a way I feel that any religion is important to a certain community, family, group in general. Those people enjoy living by those rules even when it doesn't benefit them, simply because it is just so much more simple not to decide your life. When you outsource and you have a rabbi, priest or whoever telling you how to live your life you don't have to think, to make decisions, to suffer. Because even when following what your wisdom guy says makes you suffer, you do have the comfort of knowing you are following the rules, so you are "right". Anyways, in short, it is easy to have a religion, you just read your manual (Bible, Torah, Koran...) and abide by the rules.