Faith
haha, I think it is something at the core of a human that might be described as an insecurity in life.
They need some answer.
And if you (or science) can answer where a 'soul' comes from, then pretty much all religion and faith ends.
How physical life came to be can be answered, but not everything can be, and I guess some people, regardless of intelligence have their own answers.
Some people need religion like they need water and air which is fine by me as long as they do not try to shove their beliefs down my throat...live and let live...