It's when a religion claims their supreme deity to be supreme over all others that we have a problem, otherwise there would be no holy wars in the past. Religion was invented to boost political superiority, granting the powerful right to exploit the poor. On the other hand, religion was invented to keep poor losers under control by telling them they will be rewarded for their suffering in heaven,to prrevent a revolution. It's very simple. Had the Roman emperor Constantine not endorsed Christianity as the new official religion with political backing, nowadays the Church would still be reduced to groups of people handing out leaflets like Jehova's Witnesses. The same goes for Islam. Without politics, they'd be two cults with a rather limited outreach.