The problem of evil still crops up in my theological discussion groups, as it will likely ever do, so I wanted to just get my perspective out there on the topic.
If God exists and possesses genuine omniscience, then God does not merely know all possible outcomes, God knows the single, concrete future that will actually occur as a result of any creative act. God doesn’t create “a world with possibilities”; God creates this world, fully aware of every consequence that will follow from that act. God’s knowledge cannot be wrong.
That means suffering is not something that merely 'happens' to occur after creation. It is something God knowingly permits by choosing to actualise this particular world rather than another. There is no meaningful sense in which God is surprised by suffering, nor any sense in which it escapes divine foreknowledge.
At that point, appeals to free will don’t do the heavy lifting people think they do. Free will might explain why some moral evils occur, but it doesn't explain why a world containing earthquakes, childhood cancers, parasitic disease, or millions of years of animal suffering was the one selected. Nor does free will require this amount, this distribution, or this intensity of suffering. Those are features of the world God knowingly brought into being.
What makes the problem sharper is God’s own moral framework. According to theism, God himself recognises that certain states of affairs are genuinely evil. God condemns injustice, suffering, and harm. If God could have prevented an instance of evil without undermining any greater good, then God, by his own standards, would have done so. Yet vast amounts of suffering exist that serve no clear redemptive, moral, or developmental purpose; suffering that does not build character, enable free choices, or lead anyone toward the good.
At that point, the issue isn’t whether some suffering could exist in a meaningful world. The issue is why an all-knowing, all-powerful, and perfectly good being would actualise this world rather than a morally superior one; a world with less suffering, or at least suffering that is tightly connected to goods that clearly require it.
Saying 'suffering is just part of life' doesn’t solve the problem, it simply restates it. Life did not have to be this way unless God either could not do otherwise, did not want to do otherwise, or does not exist as described under Christian theology. And appealing to heaven only intensifies the issue; if a future world without suffering is possible and meaningful, then suffering cannot be metaphysically necessary for experience, freedom, or value.
The problem of evil is not a demand for a painless fantasy world, it is a challenge to the internal coherence of classical theism. Given God’s foreknowledge, creative responsibility, and moral standards, the existence of apparently gratuitous suffering is exactly what we would not expect if such a God existed, and exactly what we would expect if the universe were indifferent to suffering altogether.