Monotheism and the Problem of Evil
There is no problem of evil for polytheism, which for the theist is a good argument for polytheism. If there are three different gods who are, respectively, omniscient, omnipotent, and all-good, then it is quite clear how there could be preventable evil in the world: the omniscient god knows it is there but is powerless to prevent it or doesn’t care; the omnipotent god can prevent it but doesn’t know it’s there or doesn’t care; and the all-good god would fix it if he could but he doesn’t know it’s there or is powerless to do anything about it. It is only when there is a single god that the problem of evil arises, because he combines all three attributes. Thus monotheism has a problem of evil, and that threatens to undermine monotheism. Some may maintain that it refutes the existence of a single god instantiating the three attributes that give rise to the problem.
But actually it doesn’t refute the existence of such a single god–unless, that is, we make a dispensable assumption. We have to assume that the single god has the three attributes at the same time. Suppose that God is omniscient on Mondays and Tuesdays, omnipotent on Wednesdays and Thursdays, and all good on Thursdays and Fridays (on Saturdays he sleeps)—but he is never all three things at the same time. Then if a bad thing happens on any given day he might not do anything about it through lack of knowledge or lack of power or lack of goodness. We only get a problem of evil if he has all three attributes continuously—which is tacitly assumed in setting up the classic problem of evil. But this is not logically required by a monotheism that postulates a god with the three attributes in question: we could postulate a god that has the attributes discontinuously. That is still a single god—so we are not postulating polytheism. Nothing about the attributes themselves logically requires that they be possessed simultaneously; that is just a dispensable assumption. One god could be omniscient, omnipotent, and all good, but he might not be all three things at any given time. So monotheism does not by itself generate a problem of evil, even assuming that God has the traditional three attributes.
So here is a way out of the problem of evil for the convinced theist: postulate a god that does not have his characteristic attributes at the same time. This seems a minor theological amendment, allowing God to have all the powers he is traditionally supposed to have: creating the universe, performing miracles, existing in heaven. The advantage is that it exonerates God from any responsibility for evil. On his omniscient days he knows about all evil but is not be able to do anything about it; on his omnipotent days he has the power but he lacks the knowledge; on his all-good days he might lack both knowledge and power. In fact, we can remove the problem of evil even while assuming that God is continuously good: he might be all good every day but lacking in knowledge or power on certain days—then some evil could escape his powers of remedy. Indeed, we can resolve the problem just by supposing that he lacks one of the attributes on certain days, so that evil could occur on those days that he cannot remedy. It is just that evil does not occur only on certain days of the week, so we can infer that God is not disabled in the regular way I described. Still, logically, evil could exist in a world with a god who is omniscient, omnipotent, and all-good, so long as he is not all three things simultaneously at all times. A brief lapse in omniscience would be sufficient. To be sure, this would be a reduced god, compared to the usual conception, but at least it is a possible god, given the cogency of the problem of evil. I can imagine a heretical religious sect occupying this position in theological logical space.