1. Couldn't god find a better way to bring about good than via evil? (Or, if you prefer, can you get creative and at least contemplate ways that appear, on the very surface at least, better?)
These types of questions are difficult because they entertain the idea of a perfect being while suggesting that said being is doing things imperfectly. I honestly don’t know if he could do it better because the existence of evil draws our attention beyond the here and now and thrusts into ultimate questions which in turn makes us consider eternity. The very existence of a non-temporal God and our temporal existence has built into it imperfection and dependency which leaves the capacity for evil. And for some reason, unexplained to man, God’s plan included a damaged creation being redeemed through the death of his son. Just because we can’t conceive of an explanation doesn’t mean there isn’t one. And honestly, an infinite being explaining his infinite perfect plan to finite imperfect creatures means by default we won’t fully understand because our very nature is opposed to complete infinite exhaustive understanding. So the absence of an explanation doesn’t necessarily prove anything, other than what we should assume to be the case given the nature of an ultimate perfect plan and our limited imperfect abilities.
2. Doesn't the process of creating a negative and a positive equal a zero?
Not if the ultimate sum of all things is good. The evil actions of men are finite and temporal, God’s plan is eternal. In other words, his actions and will are going to bring about eternal incorruptible good while the evil intentions and actions of men bring about temporal evil and are part of an ultimate plan for ultimate good. So, Christ being killed was temporary and evil, but it brought about a greater, ultimate, and incorruptible good: the salvation of many.
Then I was asked why the buck stopped at us and why didn’t God deliver the girls in Cleveland. Well, if he brings about all things, then God is the one who ultimately delivered them from the hands of the oppressor. Now, the question remains, why didn’t God do it before they were raped? The short of it is, we don’t know, and we don’t always get a clear 1:1 like we do in the story of Joseph or the death of Jesus. Maybe it will increase awareness in the area and keep a greater number of girls safe from abduction and rape? Maybe it will be so shocking and terrifying to the public that someone considering doing something similar decides it’s better not to? Again, we see things on a temporal scale while God sees a big and ultimate picture. So maybe the good never comes in our lifetime or is even tangible. Maybe someone reads this discussion or those like it and finds hope in their suffering knowing there is some underlying current of good in their awful circumstance and they face it with hope rather than despondency and bitterness? But ultimately, I don’t know. Again, the Gospel shows me that the worst thing ever brought about something wonderful, so I can, as Paul says, grieve with hope.
And to clarify, my point was not that we need God to tell us evil exists. My point was more of a philosophical flipping of the coin. Say there is no God, no absolute measurement, nothing supernatural, nothing above the natural realm, then how do we claim metaphysical realities like evil exist? How do we grieve with hope? How do we maintain in one hand that evil exists, and in the other, provide hope for the damaged, the suffering, and the down trodden?