Plato was both polytheistic and monotheistic. He believed in gods but he also believed in one great God which he called Demiurge. He believed that God made the universe and man out of pre-existent material. The forms that we see are logical and mathematical symbols which portray God to us. The highest form is good, then comes truth, beauty, justice and so on. Plato had no use for faith and believed that reason and mathematics were the means of acquiring truth. In the Republic, Plato appears to say that justice is that which the majority of people think it is, therefore the will of the people is the means of having the guidance of God. For these views, Plato is called the Father of Modern Democracy. Plato, in his famous Myth of Er, was the first to advance the notion that the soul of natural man is immortal. This humanistic and fanciful doctrine is embedded in Christianity to this day. Many people believe that it is biblical, though the Bible does not say this.

Augustine called Plato the pagan who came the closest to Christianity through natural reason of any man who ever lived. Platonism can be encapsulated as: Substituting reason for faith as a means of knowing God and truth. The enormity of the influence of his thinking on the Church can be seen in such things as Enlightenment Theology and Evangelical Conservative Theology. Many unorthodox theologians, such as F.A. Schaeffer and C.S. Lewis adopted his methodology as the way for man to know God and truth.