Philisophical writings on the consequences of biology as a basis for belief

Can you point me to writings on this specific topic? I am interested in the theoretical and the practical. If it is found to be proven fact that our health is affected by whether or not we have spiritual beliefs, what are the consequences. If we feel unavoidable biological urges such as Freud admitted to later in life, should we believe? I have noticed that many proclaimed atheists have decided to have children, which is, it seems, an irrational thing to do, but is based on biological urges/necessity and health/fulfillment. That thought led me to these questions. I am really not looking for specific answers to them, but rather the logical arguments as far as they go in their current state. I also tangeted down Church of Scientology lane, a seeming contradiction in terms. Could this be an example of ‘scientists’ fulfilling a biological spiritual urge?

::Beckons Mr. Thread to stay put::