Your personal take on “The Problem of Evil?”

[Mudhammam]

Even if notions of good and evil could only be established subjectively at best, it wouldn't amount to the claim that evil does "not actually exist" any more than it would entail other subjective qualities to be actually non-existent as well, such as beauty or love. Those states certainly exist as real, distinctive qualities of experience; the question as to whether they exist objectively or subjectively, however, is separate altogether. There could also be the possibility that evil or beauty are objectively quantifiable, yet we lack a comprehensive method to concretely establish such facts.

I don't think there's any fatal dilemma for the question of evil's existence in acknowledging that, to quote J.L. Mackie, "some kind of idealism has a played a significant part, providing some justification or excuse, however misguided," in most atrocities that one can cite from human history or the daily newspaper. To quote Francis Hutcheson, writing in 1725, "It is not a delight in the misery of others, or malice, which occasions the horrid crimes which fill our histories; but generally an injudicious unreasonable enthusiasm for some kind of limited virtue." (italics mine)

If we're deriving our sense of good and evil from human (and maybe some inferred animal) experiences of pleasure and pain, using scientific principles as our guide, I see no reason why evil cannot be considered objectively. Maybe you'll assert that this is already to assume too much, but I can conceive literally no other conversation, even that of discussing the truth of twice two equalling four, in which an opponent is restricted from feigning skepticism and doubt. At such a point it may be best to simply terminate said conversation.