Studying the relation between religion and morality is an essential problem in the new theology, philosophy of religion and ethics. Danniel C. Dennett, the contemporary physicalist philosopher of mind and a horseman of new atheism is one of the researchers of the subject. Some parts of his studies include the way of achieving ethical knowledge, specialy from the view point of its relation to religion. Not only he rejects relying on religion in this field, but also introduces it as far away from human understanding. Therefor he knows ethical naturalism and secularization of morality something unavoidable. The present issue, however, is to study the mentioned view and evaluate it by a rational analytical glance. The conclusion is that Dennett has not pressented an exact report of religious ethical knowledge, nor has given a reliable evaluation of it. He can not also replace a better idea and his evolutionary foundation can bring about no considerable outco.