God, jesus, the bible, all just seem like barriers of morality that keep societies of people from going anarchist. I mean if we did not have morals to live by or an afterlife that was more than darkness, why would people live together in peace? I think the concept of god was created early on so that people wouldn't commit murderous crimes, steal, etc etc. for fear they won't go to "heaven".
Although what I said is probably obvious to most of you, its just my take on your arguments.
Science can really explain why people are on earth, I mean biology can explain how the earth was created, to when the first cell divided and how the first autotrophic organism evolved, and how the earths gases changed to suit humans.