i think God was just a way to give people, in a time when life was truely hard, a hope that one day they'd have thier own paradise. This still applies to many who lead lives full of suffering in war-torn countries, but for the rest of us its just a bonus to a life that should be more than enough for us. Its also another way for people to try try and justify hate and prejudice caused by fear. This is still true in many places, though not as severe as it used to be (eg the crusades). Religion's failing nowadays, mainly because we've started to embrace our fellow man instead of trying to kill them, so we no longer need a reason to justify killing them. Religion isnt all bad, believing in God obviously doesnt automatically make you some kind of Nazi, and people working for God do very good things, charities, helping the poor/sick, but we shouldnt do these things just to benefit ourselves (ie get into heaven)
I think eventually we'll be able to exist without having to believe in a higher power of some kind, but it wont happen til we grow up properly and realise that he was never really there and we dont need him to justify our actions be they good or bad. I could go on like this forever, but Im gonna spare y'all