Some theists attempt to lessen the problem of evil by arguing that evil has no independent ontological existence: instead, it is merely the absence of good.
Let’s consider that defense for a moment by trying out the logic in an analogous case. Imagine that Mr. and Mrs. Jones leave town for the weekend and they allow their son Jack to watch the house. When they return, they immediately notice that there is a large hole in the living room wall. “Jack,” Mr. Jones angrily says, “Where’d that thing come from?”
Jack replies with a smile: “Dad, that hole isn’t a ‘thing.’ It’s merely the absence of wall.”
What do you think Mr. Jones will say in reply? I’m guessing he’ll say “Okay smart guy, where’d that absence of wall come from?!” (Then he’ll cuff Jack on the ear.)
You see, the problem isn’t with the metaphysics of holes. It’s with the damage to the wall. And the problem of evil isn’t with the metaphysics of evil. It’s with the damage in creation vis-a-vis suffering.