"Consider the idea of God. We do not know how it arose in the meme pool.
Probably it originated many times by independent 'mutation.' In any case,
it is very old indeed. How does it replicate itself? By the spoken and
written word, aided by great music and great art. Why does it have such
high survival value? Remember that 'survival value' here does not mean
value for a gene in a gene pool, but value for a meme in a meme pool. The
question really means: What is it about the idea of a god that gives it its
stability and penetrance in the cultural environment? The survival value of
the god meme in the meme pool results from its great psychological appeal.
It provides a superficially plausible answer to deep and troubling
questions about existence. It suggests that injustices in this world may be
rectified in the next. The 'everlasting arms' hold out a cushion against
our own inadequacies which, like a doctor's placebo, is none the less
effective for being imaginary. There are some of the reasons why the idea
of God is copied so readily by successive generations of individual brains.
God exists, if only in the form of a meme with high survival value, or
infective power, in the environment provided by human culture."
[Richard Dawkins, "The Selfish Gene"]