Michael Horton writes: "Among the caricatures of Calvinism is the widespread claim that it renders God the author of evil, suffering, sin, and even the fall of humanity itself." However, both Calvinist and Arminian theologies teach that God knew beforehand that Adam and Eve would fall into sin, yet he created them anyway. This logically leads to questions such as. . .
If God knew that Adam and Eve were going to transgress his law, why didn’t he change the circumstances so that they would have made a different choice?
Why would God create people he knew would be condemned for their original and actual sin?
Horton argues that those questions pose a "vexing challenge" for Arminians just as much as for Calvinists, and it has nothing to do with predestination, it has to do with foreknowledge. Since Arminianism affirms the comprehensive foreknowledge of God then it is vulnerable to the same charge Arminians often fling at Calvinists -- that our theology turns God into some sort of moral monster.
Taking on this question in a blog post is a little dangerous. For a statement of the Reformed position and its scriptural basis, I’d refer readers to For Calvinism.
However, there is one point that is worth pondering briefly: Non-Calvinist theologies are just as vulnerable on this question. Classic Arminian theology shares with Calvinism—indeed with all historic branches of Christianity—that God’s foreknowledge comprehends all future events. There is nothing that happens, nothing that you and I do, that lies outside of God’s eternal foreknowledge.
Now go back and read those questions above. Notice that they don’t refer to predestination, but to mere foreknowledge. They pose a vexing challenge not merely to Calvinists but to anyone who believes that God knows exhaustively and eternally everything that will happen. In other words, everyone who affirms God’s exhaustive foreknowledge has exactly the same problem as any Calvinist. If God knows that Adam will sin—or that you and I will sin—and could keep it from happening, but does not, and God’s knowledge is infallible, then it is just as certain as if he had predestined it. In fact, it is the same as being predestined. Then the only difference is whether it is determined without purpose or with purpose.
Horton goes on to discuss that difference. He also talks about how strains of hyper-Calvinism and hyper-Arminianism both share the same impatience with mystery, and cautions against pitting Scripture against Scripture in order to achieve rational satisfaction. Like everything Mike Horton writes this is balanced and charitable. Read the whole thing here.