Religion- belief or force of seperation

Sometimes I really wonder about religions. I think I might have said this once before about my own religion, but now I mean it about every single one. I look at the main ones: Judism, Christianity, Islam; about the first ones: Zoroastrians, Judaism, Buddhism; at the spiritual ones: Sufism and Buddhism.
Do not laugh at me: I do not see any difference between any of them. Sure, small ones, something like: pray this time of the day and do not eat this, etc. These are not major differences. These are the ones all the shirts in your closet have: one in blue, one in green, one linen, and the other silk. Nevertheless, they all have one thing in common: they are all shirts, covering most of the upper part of your body. I don’t think you have to separate them in your closet (well, I admit, I hang mine by their colors, this makes it easier to pull them out in the morning…  ) You do not have to watch your shorts in order to avoid a battle ion your closet, one saying it looks nicer pr is better, just because there is a designer label on the back. The other one answering: No, but I have this fashionable color. So, no you tell me: why do human beings, who claim that they are the highest creature on earth, keep on fighting and killing each other just because each group thinks that the way they praise their God is the one and only true way? Huh??? I mean, come on, should religion mot be about doing good, having respect, not betraying, not killing? Should it not be about how to think about your common creature? Regardless of what these people say: I believe that there was the same creature for each one of the groups! Should we not all look at the common de-numerator instead of the small differences? You could not possibly think that even one single person who kills the other one because of a different believe is thinking about their God in that moment. They just think of their own power, proving that they are right and the other one is wrong. Should religion not bring people closer? Unfortunately, it kills, and pulls people apart. What a shame. This is the moment, where I think that human are not the highest creature, but the lowest ones. While we invent one thing after the next, send people to the moon and fly to Mars, while having cell phone, iphones, and flat screens, we are still killing each other in worse ways that in the animal kingdom. If you look at history, starting from the Zoroastrians, who killed the prophet Mani, the Arabs, who killed Zorastrians, the Jewish who kill Moslems, the Hinduism, who think no one outside their cast is pure. What is this? I know it might sound like in a fairytale, but how can you kill someone for the way they worship their God? Is there a rulebook for what is right and wrong? Should that not be a very personal matter? This is the time when I truly belief that religion is not the belief of a person, but the force of to separation, the force to kill.