Why do you treat natural evil and moral evil differently?
1. The first thing that comes to my mind as to why that is the case is that there is no morality in a flood, hurricane, or in cancer. Cancer is not deciding to kill me. Floods are not deciding to kill my children. They just do it. So there's a huge difference immediately.
False ideas, however, emerge out of a volitional, intellectual context, which in the emergence is evil. It's wrong. But with cancer and hurricanes, there's no morality there.
Whoever wrote this question thinks that whenever I consider, say, Open theism, I don't respond with the sense that this is a sad and providentially-used tidal wave, breaking on the church like a tsunami in Sri Lanka and wiping out tens of thousands of people.
And that's an accurate observation. I don't respond the same. That's because the Bible treats false teachers as blameworthy and responsible for foisting this hellish tidal wave on the church! And it holds them responsible for it!
Maybe the effect this question should have on me for improvement is that I should ask whether there is a Satanic volition behind tidal waves, hurricanes, and cancer that is killing people, because Satan is a murderer. So I should have the same kind of moral reaction to him that I do against, say, progenitors of destructive false teaching. And I should! Yes, that's right! I should feel very angry at Satan. And I think I do. I don't like Satan. I am angry at Satan.
So that's one way that they're different: the origin, the volitional origin of a false doctrine and the non-volitional origin of cancer or a tidal wave. They don't have a mind or a will of their own. They're being produced by God for his good purposes, whereas the false teacher is not producing these for good purposes.
I am willing to ask the question, "Will God turn false teaching for ultimate good?" He will. But the way he does it is by our strong opposition to the false teachers. In other words, making the judgment that a false teaching that arises will one day turn out for good doesn't nullify the means that God might use to get it there, namely, the opposition of the church.
Paul said, "It is necessary that there be factions among you, that the genuine might be obvious" (1 Corinthians 11:19). Well, that doesn't mean that when the false teacher emerges, nobody should create a faction because God is going to work it all out for good in the end. You do create a faction, and you say, "That will not be taught in this church! That is demonic, horrible, and it hurts people"--which is what I believe about Open theism.
2. Besides their different origins, a second difference between natural and moral evil would be that the destruction wrought by cancer is not a hellish destruction. It doesn't condemn anybody. It doesn't produce unbelief in the people that it kills, whereas false doctrine by its very nature is telling people God is not like he says he is. That's not what a cancer does, at least not if it is being handled pastorally with wisdom.
The way a pastor handles false teaching with wisdom is by pointing out to people, "This will kill you. You believe this, and it will kill you forever. No cancer will kill you forever; no tsunamis will kill you forever; but this teaching will kill you forever. If you go where it's going, it will destroy your soul."
And so both the effects and the origins of natural evil and moral evil are different.
That's a very provocative question. I'll have more to think about it.