ok, i didn't have time to go reading through peoples posts, so i'll just write my opinions, sorry if they've been discussed already.
Firstly, i'd like to say that whoever came up with the idea of religion was someone very level-headed and clever. From where i am standing it looks like many years ago, the whole world was in turmoil, everyone was fighting, everybody was frightened, they had no rules to go by, they had no destiny and no future. In death, they had nothing to look forward to.
Someone, seeing all this madness, created a dream, a set of rules to live by, to give people hope, something to live for, a destiny. This person, realized that the world needed order, and that no one man could do this, so a father figure beyond this world would have to be created (eg god). With this in mind, people could beleive, hope and dream. Also, because god is not a mortal, a human being, he can be in more than one place, which stops people being tempted into making mistakes (with a human, it would be easy to go behind peoples backs, with god, he can see everywhere, to keep order). No-one could ever deceive, this outer being, their every move was being watched, in a sense they were being judged and this is what people were scared of, so they made sure they stuck by the rules.
Because, when these "religions" were created so long ago, there could be no single one, because communication thousands of years ago was unheard of, each idea originated in its own seperate area in the world. Each person, with a vision, of a founder had different idea's and that is why no religion is the same, because people have different ideas on how to control millions of people.
Also, all these years ago this person, who comes up with the religion, has to fit his god into society, as no-one at that time knew how the earth they stand on was created, this "founder" gave them a believeable story, and so they would realize the importance of the "god" and abide by his rules. All the questions about how the earth could be answered easily, thus eliminating confusion (eg, how was my dog created?, the god created him, how did the earth come around? God created the earth, for all of us to live in peace)
There is one phrase that i can backup my theory with "one man is clever, a million men are stupid", eg someone realized this, and being a single person was clever enough to control the million. Clever huh?
And so, the clever man made the million, not clever, but not uncontrollable.
I could tell you all how i think the universe would was created, but thats for another topic
Well, thats something for you all to ponder on.