What’s the worst thing that would happen if there was no religion? You just die. You cease to exist. You don’t got to heaven and see all your dead relatives. (Good news: you don’t go to hell either).
Religion was invented out of fear of death. Christianity touted, ” If you believe in Jesus, you do not perish, but live an eternal life”. (If that were true, we’d still be on our first Pope.) The movie “The Invention of Lying” nails this concept.