"It is the mark of an educated mind to be able to entertain a thought without accepting it." -Aristotle
Let's suppose a man is persuaded by an argument from natural theology, say, the argument from change (yay!), that there must exist a monotheistic God. Let's also say he's inclined to accept the key premise of Plantinga's modal ontological argument - namely, that it's possible for a maximally great being to exist and concludes that a maximally great being does exist. Now to make things interesting. Suppose this man is also persuaded by the logical version of the argument from suffering. Should he abandon his theism (or more specifically, God's maximal greatness) just because he has become persuaded by an argument that concludes that it is impossible for God to be maximally great?
I don't think so. In fact, I think changing one's position based on two (hypothetically) equally strong and opposing arguments may be a sign of mental instability. What the rational person will do upon such a predicament is reassess the arguments for and against God's maximal greatness. If after a time he still cannot make up his mind, then he could take one of two routes: either a) continue researching these arguments, or b) adopt agnosticism with respect to God's maximal greatness.
Of course, virtually no atheistic philosopher today defends the logical version of the argument from suffering. Stephen Law, for instance, prefers instead to defend the evidential version of the argument from suffering, which only concludes that God's being maximally great is unlikely. Still, one ought to remind one's self that the arguments from suffering, even if successful, would be a far cry from constituting a demonstration of the truth of atheism. After all, one may make the more modest claim that a monotheistic God exists who is very powerful, very intelligent, and very good (or maybe morally perfect).