What if religion/belief is a preparation of the brain for the experience of death?

A kind of training that will dictate what our final experience will be. If you believe in eternal life then that is what you will experience in your final moments.

What if this was scientifically proven? Wouldn’t you want to believe in something, in order to take control of your last moments and have the best possible experience.

Would belief be possible if this was known to be true?