The question that strikes every individual of this generation, what is the prove of the existence of God.
True there are reports of people, saints seeing and experiencing the presence of god, but there lies no authenticity. After all, whatever we read about god, we know them from books. Books we call sashtras, but alas all these manuscripts are written by human beings.
There needs to be a rationale behind the occurrence and existence of everything, that is what science has taught us. Yes, God was created by man, to bring control in the society. Once man in the primitive era started building a society, the differences in thought and fear of uncontrollability was considered a big issue. And there was one way to solve it, make laws.
And how do you make people believe those laws? Simple, say them it's the rules by our creator, By God.
Impeccable people have come and have done great things, when the society was in danger. People like Jesus Christ, Gautama Buddha, Lord Rama, Lord Shiva, Prophet Mohammad have come to this world just like any other being. The World was in chaos, it needed law and discipline and these people were successful in bringing discipline back to the society whenever it needed. These, have made them Great Men. Karma has made them what they are.To make sure chaos doesn't spread again, humans have given them the stature of God. At least people wont want to defy the rules set by God.