I think the problem of evil can be made most forcefully when amalgamated with an argument from poor design. This is essentially the move Paul Draper makes with his Bayesian argument from evil. Draper notes that pain and pleasure serve a biological role that makes sense on a hypothesis of indifference (and is arguably a prediction of evolutionary naturalism), but is incredibly surprising under the hypothesis of a morally conscious creator.
The idea is that some features of the human design are morally significant, so that a morally concerned designer would have reason to discard or, at least, revise such design. But on naturalism, the forces of evolution are indifferent to the moral significance of the design it produces.
For another example consider how, compared to most other animals, giving birth is incredibly difficult and even dangerous for humans. On evolutionary naturalism the explanation is obvious: there were very powerful evolutionary pressures on our ancestors to have narrow hips to facilitate our bipedal mobility, and very powerful evolutionary pressures for humans to have big heads to facilitate our big brains and great intelligence. But both these traits together obviously mean a lot of trouble for birth. A morally conscious designer would see that this will cause a lot of unnecessary death and suffering and design things differently, but evolution is blind to these things as long as they don't impede reproductive fitness.
We then have two competing hypotheses: an anthropic origin by evolutionary naturalism, or by a morally conscious creator. And since each entails the negation of the other, we have strong reason to think there is no morally conscious creator.