To say that humans are composed of machines is not to say that we are merely machines. Humans are dignified machines. We are (so far) the most extropic, most complex product of billions of years of evolution.
Religion is (a) a pre-scientific system of explanation and technology; (b) a source of meaning, direction and emotional expression in life; (c) a means of social control; (d) a means of coping with uncertainty and death.