The standard objection to Calvinism is that predestination implicates God in evil. I've fielded that objection on multiple occasions, so I won't rehash my arguments. I will say that it comes down to two stark alternatives:
i) Every evil happens for a good reason
ii) Evils happen for no good reason
Whichever box you check, it will be a hard truth.
But now I'd like to draw attention to one of the practical values of predestination. Nabeel Qureshi is a Muslim convert to Christianity. He's become perhaps the most high-profile Christian apologist who specializes in Islam. Lately, he's been struggling with what, if nature takes its course, is terminal cancer. He's done a running series of videos updating his diagnosis and treatment. Here's the latest:
It's painful to watch these videos in chronological order, because he starts out very upbeat and optimistic, but is forced to move the goal post as his prayer for miraculous healing goes unanswered (thus far). In earlier installments, he talked about how Scripture encourages "presumptuous" faith. (What Sam Storms calls "expectant faith"). He said in light of this that he must believe God has in fact healed him. But sadly, that hasn't happened.
In his latest update he says Jesus healed everyone who came to him, or everyone who was brought to him. He infers from this that it is God's will to heal everyone.
The problem with Nabeel's position is that, despite the best of intentions, his setup means faith in Scripture is bound to lose. Even though he knows in advance that God doesn't miraculously heal everyone, or every Christian, he's pitting Scripture against undeniable experience to the contrary. But that guarantees confusion and disappointment at best, and bitter disillusionment at worst.
What he needs is a more robust theology of providence. It's a false dichotomy to pit Scripture against providence. To some degree, we can infer God's will from providence. For providence mirrors God's decretive will. The past is the record of God's plan for the world, up to that point.
So there's nothing faithless about inferring that it's not God's will to miraculously heal everyone, or every Christian in particular, from the fact that God doesn't heal everyone. History in itself, is a reflection of God's will.
I'd also point out that Nabeel's appeal to the Gospels is misleading, even thought that's not his intention. Assuming that Jesus healed everyone who came to him, or everyone who was brought to him, that's an infinitesimal fraction of all the ailing people whom he didn't heal. Most people didn't come to Jesus for healing for the simple reason that most people didn't know he existed. Outside the ambit of Judea and Samaria, he was unknown. So consider all the ailing people who never had an opportunity to seek him out for healing. Not to mention people living on other continents.
And that's just in reference to his public 2-3 year ministry. Consider the multiplied millions of people throughout human history whom God hasn't healed, both before and after the Incarnation. So Nabeel's sample is quite unrepresentative.
Which is not to deny that some people are miraculously healed. But he's framed the issue in such a way that faith in Scripture will inevitably be dashed by rude experience. That's a recipe for professing Christians to become alienated from the faith. They had a false expectation, based on their misunderstanding of Scripture. When that collides with unyielding reality, they lose their faith. Or, at the very least, suffer a crisis of faith.