Religious affliliation affects our health because it affects our mental state. According to Seward Hiltner, "attitude and feelings (which we think of as psychological) profoundly affect muscles and body fluids (which we think of as physiological), for better or for worse, for illness or for health." Religion is strongly associated with feelings of either fear or faith, which are opposite of one another. Fear can drice out faith and faith can drive out fear. Psychological issues like deeply ingrained fear can induce or prolong illness, so research is being done to find out if the same is true in reverse.