We pray because we believe the Divine Will recommends and demands it. The possibility for a naturalistic account of the psychological benefits of prayer is not a problem for us; for although we tend to speak of prayer in terms of the divine--e.g. that God wants us to pray, that God communicates to us in prayer--we do so because such and only such is our belief, not because it is also our belief that a complete knowledge of the human mind would reveal some miraculous subversion of the natural order during prayer.
Consider analogously our tendency to speak of the commandments in terms of Divine Will, even though we do not believe we obtain the knowledge of particular commandments by a miraculous infusion. On the contrary, the prohibition of murder for example is the clearest case of natural law. Hence naturalistic accounts of the genesis of this and other moral norms are not problematic by their possibility, and by their actuality can even be, while not the whole truth, at least wholly true, in so far as they are properly naturalistic. That is, so long as they remain positively natural and not negatively supernatural.
