We can get along, but we are all different. We all have different visions of the world, of what is good and bad and all that stuff. I believe the only "bad" thing out there is the dogma. We're all different, why we should believe in the same thing?
I see the whole energy of the Universe as a God. "God is in all of us", "matter is only another form of energy", well, you get it, that's how I see it.
There is always room for discussion because discussion is good. The bad thing is the mind-closing that just reject others, and then those "others" reject more people and then you have war and all that... You can apply it to politics if you want: "why don't the candidates get all along if they are supposed to help the country?" ^see the reasoning up there^
Maybe if we could respect others instead of rejecting them, things would be easier...
As for the similarities in religions, I guess it's humans' societies nature, maybe a human society with other values would have had less possibilities to survive. There are more factors, but we can't deny that that has its influence.