Deep down, however, much more complex he may be, man remains on this view an animal only. And the significance of morals is purely functional, furnishing somewhat of a guarantee of self-preservation. It is obvious that scientific naturalism insists on the continuity of man with the rest of nature in evolutionary terms. If man be simply a verbalizing, tool-using ape, an illegitimate child of a thoughtless evolutionary thrust, then only nature or man's aspect of nature can introduce the least particle of optimism into an inevitably pessimistic outlook. Not only are sacred truths explained away, but the temper of the times is to attack Christianity vehemently for persisting in superstition in the midst of scientific innovations to the supposed contrary.
Religious belief is simply an irrational deception of the unconscious.
Eschatological notions are seen as compensations for failure to achieve in this life. As Sidney Hook says, In a world full of dangers and surprises, in a world of time, pain and contingencies, it is not hard to understand the psychological place of religion . . . As to prayer, it is good psychological exercise and may have the therapeutic value of unburdening the troubled mind or cleansing the conscience. Sin is for the naturalist nothing more than unfortunate home conditions combining with a predisposition for anxiety. The result is neurosis, the cure of which is often to calm down the conscience and remove the guilt that has resulted.