How could evil come into existence when from creation nothing but good had existed? That anything may come into existence, it must have its origin. Good could not be the origin of evil, because evil is nothing of good, for it is privative and destructive of good. And yet as it exists and is felt; it is not nothing but is something. Say, then, whence comes this something after nothing.
… no one is good but God only, and that there is not anything good which in itself is good except from God. He therefore who looks to God, and wills to be led by God, is in good; but he who turns himself away from God and wills to be led of himself is not in good, for the good that he does is either for himself or for the sake of the world; thus it is either meritorious, or is simulated, or hypocritical. Whence it is plain that man himself is the origin of evil. Not that this origin was inherent in man from creation, but that by turning away from God he imposed it upon himself. That origin of evil was not in Adam and his wife, but when the serpent said:-
In the day that ye eat of the tree of knowledge of good and evil, ye shall be as God. (Gen. 3: 5)
and because they then turned away from God and turned to themselves as to a god, they made in themselves the origin of evil. To eat of that tree’ signified to believe that he knows good and evil and has wisdom of himself, and not from God.
… How could man turn himself away from God and turn to himself, when yet man can will, think, and therefore do nothing except from God? Why did God permit this?
Man was so created that all that he wills, thinks, and does appears to him just as if in himself and thus of himself. Without this appearance man would not be man, for he could not receive, retain, and as it were appropriate to himself anything of good and truth, or of love and wisdom. Whence it follows that without this, as it were living appearance, man would have no conjunction with God, and therefore no eternal life. But if from this appearance he induces on himself the belief that he does will, think, and therefore do good of himself, and not from the Lord, although it is in all appearance as if of himself, he then turns good into evil within him, and thus makes in himself the origin of evil. This was the sin of Adam.
… love without wisdom is love from man and not from the Lord. And this love, because it conjoins itself with falsities, does not acknowledge God, but itself as a god; and this it tacitly confirms by the faculty of understanding and of becoming wise, as if of himself which is implanted in him from creation. This love therefore is the origin of evil.