...one of the great difficulties about writing a book or play
about the Devil is to prevent that character from stealing
the show.
...the role in any handling of the subject is sure-fire --
not only in the sense that the Devil is a picturesque figure
of color and action; that is true of any vigorous villain.
But it is also true in the sense that the Devil is only too
likely to capture the sympathy of the house. (....)

It is not, of course, surprising that the devil should appear
attractive .... it is precisely the Devil's business to
appear attractive; that is the whole meaning of temptation
to sin. And unless the artist conveys something of this
attraction, his devil will be a mere turnip-ghost, exciting
either boredom or derisive laughter, and in no way conveying
or communicating the power of evil. ....

...the old difficulty about omnipotence and free will.
If God is almighty and created everything, how do we account
for the existence of the evil power, or of any sort of evil
in creation?
One answer - that of the Manicheans - is to deny that God is
omnipotent and to allow the coexistent presence of two powers:
good and evil, light and darkness.
Even in this scheme of things, it is generally supposed that
the good will eventually conquer the evil.
But the supposition behind is that evil and darkness are as
primary as the good and the light.
A variation of this is that the darkness is primary; that it
existed in chaos or the abyss before the light got to work
upon it, and that the light - what we mean by God - is
continually engaged in building up creation toward the good
against the backward drag that seeks to reduce all things to
the primeval chaos. This position .... lies behind a good
deal of Berdyaev's philosophy; and seems to have a good deal
also to do with the fashionable doctrine of emergent evolution,
by which God is supposed to be evolving himself out of chaos
in an enormous time process.

The orthodox Christian conception is more subtle and less
optimistic; also much less involved in the time process:
the light only is primary; creation and time and darkness
are secondary and begin together. Considering 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 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 at this point it becomes possible for the evil and the
darkness and the chaos to boast: "We are that which was before
the light was, 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.
Such is the primary illusion inside which the devil lives and
in which he deceives himself and others.

That primary illusion is stated with perfect clarity by Goethe's
Mephistopheles:

Ich bin ein Teil des Teils, der Anfangs alles war,
Ein Teil der Finsternis, die sich das Licht gebar,
Das stolze Licht, das nun der Mutter Nacht
den alten Rang, den Raum, ihr streitig macht.

That is the Devil's claim, the exact statement of the pride
by which he fell from heaven. It sounds extremely fine; and when
it is set forth in attractive language, it is sometimes difficult
to remember that the Devil is a liar and the father of lies.
In Paradise Lost , we find Satan making the same claim....
...he shows himself a poor logician, ...suppose that by this time
he really believes in his own claim - or has argued himself into
the illusion of belief; for the corruption of the will saps the
intellect, and the Devil is ultimately a fool as well as a villain
... the victim of his own illusion.
..In The Devil to Pay , I tried to make this point