The concept that all people follow a "Cosmic Carrot" of some sort. This is an analogy regarding the similarities in the moral drive religions have using the old "Donkey and the Carrot" symbolism. We pull that cart because we think we are getting closer to the carrot.

"If you are good in this life, you will be rich and healthy in the next life.

"If you don't sin, you go to heaven."

or, to dissect things further:
"If you [Donkey] die in battle [Cart to pull], then you get to go to Valhalla [Cosmic Carrot]."

I am not even going to get into the fact that along with the cart, we tote the carrot as well :P