This is part of a larger paper that I am writing and working on. Law’s “Evil-God Challenge” is simply a section in the paper. In coming across Law’s “Evil-God” challenge, I’ve seen numerous Christian philosophers offer up an explanation to how we can know God is good (such as Edward Feser). While all make good points, I think they are overcomplicating the issue and that the answer is actually quite simple. Hence, I post part of my solution here:
One must understand that God is wholly good and not imperfectly good, or good with a little bit of evil. God is a whole and must be perfect. To use the language of Robert Spitzer, since God is the unconditioned reality (nothing precedes Him), by logical necessity God must be simple (not composed) and perfect (lacking in nothing). Since God is perfect, He must either be good or evil, and wholly so. He cannot be both (as this would violate the law of non-contradiction).
Therefore, if God were evil then He would be perfectly evil. Were one to treat evil as a substance (which is difficult to imagine), one would ask what is at the core of all evil acts. Through a simple use of deductions, one would easily arrive at the conclusion that pride is at the core of all evil acts. Yet, pride can still be used in some good ways when it is used in moderation. In its extreme, however, pride is motivated by narcissism, or extreme love of the self. The more narcissistic a person is, the more apathetic he is to those around him. Narcissism requires the love of the self to the exclusion of all others. A narcissistic mother does not torture her baby; rather she neglects the baby if the baby interferes with the mother’s desires. Therefore, if God were evil He would be the ultimate narcissist.
If God were the ultimate narcissist, then nothing would exist; since something exists, it shows that God is not a narcissist and therefore God is not evil. If the root of evil is narcissism and narcissism is the focus on the self to the exclusion of others, and if God were wholly perfect in all things, then God would be too focused on Himself to have ever created anything to begin with. Yet, something exists. Therefore, God is not evil, which apophatically means God is good.
Turning to Stephen Law, one reads,
“Consider a diﬀerent hypothesis. Suppose the universe has a creator. Suppose also that this being is omnipotent and omniscient. However, suppose he is not maximally good. Rather, imagine that he is maximally evil. His depravity is without limit. His cruelty knows no bounds. There is no other god or gods – just this supremely wicked being. Call this the evil-god hypothesis.”
Thus, one could argue that even if God is supremely narcissistic, He created humans simply to gain pleasure from torturing them. Certainly, this would still be an act of narcissism. One could also theorize that being a narcissist God wanted other lesser beings to recognize how great He is and to serve Him fully, irrespective of how He treats them.
Law’s objection to God’s goodness holds no weight when one considers narcissism as the root of all evil. In fact, the implications of his argument actually defeat the argument. First, if God created humans in order to torture them so He could gain pleasure, this would indicate that God had a need for something. Of course, a perfect being can have need of nothing, thus if God had need of something then he would not be God.
The traditional Christian narrative concerning creation is that God created out of love, not out of need; He created as a sacrifice, not as a gain. He gained nothing out of creation, thus no perceived need was met. If God needed humans in order to be more loving, then He would not (1) be loving (as He would be creating humans for personal gain) and (2) God would not be God, as He would need something. Likewise, if God created humans to torture them, He would not be God, as He would have need of something.
Secondly, and more importantly, we can imagine a God who would create humans in order to torture them. Yet, we can think of a God even more evil that would not create humans because He would be so concentrated on Himself He would never think of humans. Therefore, the original syllogism – that because something exists, God must be good – stands true.
 Robert Spitzer, New Proofs for the Existence of God: Contributions of Contemporary Physics and Philosophy (Grand Rapids: William B. Eerdmans Publishing Company, 2010), Section II.
 One might argue that pride is not involved in natural acts of evil. However, since God is a person, one must discuss evil solely on personal grounds. In such a case, no person ever commits evil via a natural act; there is always a willful choice in committing an evil act. At the core of that willful choice is the person’s pride, or self-love. Furthermore, willful acts of evil are seemingly worse than natural acts; a Tsunami killing 200,000 people in Indonesia is horrible, yet society is more aghast at a dictator that would willfully kill 50,000 of his own people on a whim.
 Stephen Law, “The Evil-God Challenge,” Religious Studies (2009): 4. http://journals.cambridge.org/action/displayFulltexttype=1&fid=7247672&jid=RES&volumeId=1&issueId=1&aid=7247664&fromPage=cupadmin&pdftype=6316268&repository=authInst (Accessed November 30, 2011)