"You are familiar with the fact that theologians always escape from difficulties by using the word 'mystery,' and that the mystery of mysteries is the origin of sin. The great mystery is a theological one. How is it possible that a God of infinite holiness, of infinite compassion, of infinite knowledge, of infinite power, ever allows sin to exist? Why, sin is the very thing he hates. This is an absolutely insoluble mystery. How did sin begin? Why did God permit it? If we are all free, if we are created by God, and there is nothing which exists which God did not create except himself, how did sin come? That is an insoluble mystery. St. Augustine attempted to account for it, and I believe his suggestion is the very nearest to it possible. It is that sin in its origin is not a positive entity, but it is a defect.
Take this for an illustration: Suppose you have a
fiddle that has been out of tune; you hang it up on the wall, and a year
after you come back and take it down, and the fiddle is all in tune.
You know that the fiddle
must have been put in tune; it could not have got into tune
spontaneously. But suppose your fiddle is perfectly in tune when you
hang it up, and you go away, and when you return you find that it is out
of tune. It does not follow that somebody did it. You do not say that
somebody did it, but that it got out of tune. Now, in the case of Adam I
have no doubt sin began in that way; not as sin; but it began to be
through inattention, it began to be through defect in love, through
defect in faith; it was an omission, and it was thus through a rift in
the lute, through a crack here and another there, with a want of
harmony. And with this want of harmony came the awful discord that has
sent the world into a bedlam and made a division between God and man" (A.A. Hodge, Evangelical Theology, pp. 161-162; underlining mine--CD).
A.A. Hodge needs to read (presumably, again and again) and actually believe Romans 9 in order to extricate himself from this carnal and blasphemous reasoning.