I agree about it, but only in few contexts.
Religion is an opium of people.
Opium makes you feel relaxed, makes you feel good, and WILL destroy you from the inside.
Religion makes you feel relaxed, makes you feel good, and WILL fix and repair everything wrong inside you.
Why do heaven and hell exist? To make people do good deeds and to avoid bad things. You wouldn't want other people to annoy you or insult you or hurt you or even try to kill you, would you?
I think this is like a controversial topic to be discussed, but I'm only stating my thoughts.