The orthodox Christian position is . . . [that] the light, and the light only is primary; creation and time and darkness are secondary and begin together. When you come to consider the matter, it is strictly meaningless to say that darkness could precede light in a time process. Where there is no light, there is no meaning for the word darkness, for darkness is merely a name for that which is without light. Light, by merely existing, creates darkness, or at any rate the possibility of darkness. In this sense, it is possible to understand that profound saying, “I form the light, and create darkness; I make peace and create evil: I the Lord do all these things” (Isaiah 45:7).
But it is at this point that it becomes possible for the evil and the darkness and the chaos to boast: “We are that which was before the light was, and the light is a usurpation upon our rights.” It is an illusion; evil and darkness and chaos are pure negation, and there is no such state as “before the light” because it is the primary light that creates the whole time process. It is an illusion, and that is the primary illusion inside which the devil lives and in which he deceives himself and others.
In the orthodox Christian position, therefore, the light is primary, the darkness secondary and derivative; and this is important for the whole theology of evil. In The Devil to Pay, I tried to make this point, and I remember being soundly rapped over the knuckles by a newspaper critic, who said in effect that after a great deal of unintelligible pother, I had worked up to the statement that God was light, which did not seem to be very novel or profound. Novel, it certainly is not, it is scarcely the business of Christian writers to introduce novelties into the fundamental Christian doctrines. But profundity is a different matter; Christian theology is profound, and since I did not invent it, I may have the right to say so.
The possibility of evil exists from the moment that a creature is made that can love and do good because it chooses and not because it is unable to do anything else. The actuality of evil exists from the moment that that choice is exercised in the wrong direction. Sin (moral evil) is the deliberate choice of the not-God. And pride, as the church has consistently pointed out, is the root of it, i.e., the refusal to accept the creaturely status; the making of the difference between self and God into an antagonism against God.
-Dorthy Sayers, Letters to a Diminished Church