I have heard many people reduce the argument for religious systems of belief and action to their material benefit. A most cited argument is that the Book of Leviticus and its guidelines for nutrition and cleanliness prevented the Jewish people from having plagues and widespread sickness in a time in history where it was very frequent.
Or some sociologists of the Judeo/Christian persuasion cite that biblical stipulations for abstaining from pre martial sex and only having one wife are statistically correlated to stability among nations that follow the Bible's guidelines. This argument is bolstered by the observation that widespread promiscuity and polygamy are frequent among unstable nations and people groups.
My question is that does the essence of faith, that is, the substance of things unseen, loose its efficacy when the guidelines from a religion become cause and effect exchanges of practice and outcome?; Does the reduction of beleif systems to a materialistic perspective to market them to people of scientific worldview alter the original faith itself?