I don't think people do good things because they think "God will like them for it" - I certainly don't. They do it because their faith tells them it is the right thing to do..... but many people would also be doing it without that extra stimulus.
As for your assertin that belief in God will die ..... Dream on.
No, on second thoughts, humans have never been rational and there is indeed little prospect of that changing (electing Trump, etc). As you were.