[maushu]

It's much easier that way to make people self sacrifice for the religion, gives a meaning to their life and pacifies their fear of death.

[inglor_cz]

Plenty of religions don't demand self sacrifice from their adherents. Polytheist and animist creeds are very different from the Abrahamic faiths that we tend to think of when we speak about religion.

For example, the Tlingit in Alaska believe in reincarnation, but in their tribal way of life, there really isn't any compelling "use" (in the Machiavellistic sense) for that belief.