OK, your topic title is better than "A question". It's still pretty poor. How about something that actually describes the theme of the topic?
Didn't Karl Marx call religion "The opiate of the masses"? In other words, it was something to dull the pain of life and give hope for a better afterlife. As such, the root cause of religion would not be the fear of death; rather it would be the desirable anticipation of death.
My impression is that multiple universe considerations is rather a smokescreen, in the context of the topic as a whole.
Adminnemooseus
Edited by Adminnemooseus, : Changed the Marx quote from "The opiate of the people" to the probably more accurate "The opiate of the masses".