It's the age-old, soul-searing question: if God is all powerful, and if God is all-good, why does He allow terrible, obscene things to happen, especially to good people?
And I am going to tell you right away there is no direct, complete, acceptable answer to this question. There just isn't. People have been searching for it not just for centuries, but for millennia. The entire book of Job in the Old Testament asks this wrenching question. Job's friends come up with various philosophical answers, all wrong, and God never does tell Job why he has suffered the loss of his health and all his possessions and the deaths of all his children. There is an entire branch of Western philosophy called Theodicy which seeks to justify God; and every answer it proposes falls short. Worse, most of the "answers" make God out a monster.
There are partial answers, and I'm going to try to tease out the grains of truth in them and then point out (as if our hearts didn't already know) why they are not completely satisfying. Then I'll describe how Christianity does confront evil, albeit still without answering the philosophical question (as Christianity isn't a philosophy).
So perhaps the first thing for Christians to remember is that God is not the author of evil: satan is. And of course, beguiled by satan, we too are authors of evil. We hear a lot about free will in human beings, and it's true, people misuse their freedom and a lot of our misery stems from this. But this answer only helps a little, because it only pushes the question back a step: satan does it, but why does God permit him to? Or we do it, but why doesn't God protect us from suffering when others seek to harm us? Or why does He seem miraculously to rescue some but not others?
We often hear or think the crushing evil that has befallen us must be God's punishment for our sins. A young girl whose mother had died once asked me if it was her own fault because God was punishing her. Horrifying thought! No! In the first few verses of Luke 13, Jesus says the people who were killed in two separate tragedies were no more sinful than anybody else. But, He tells us, we'll all die if we don't get rid of what's killing us. He means sin.
The truth about sin is that it is self-punishing. You touch a hot stove, you'll be burned. You jump in front of a speeding train, you're (probably) going to die. You steal from someone, you rob your own soul of its/your health. You kill someone, you kill something precious at the very core of yourself. You hate someone, you poison your own life. You have a sufficiently corrupt corporation (think Enron) or country, it will collapse because instead of everybody acting in ways that support and maintain it, too many people are doing what profits them personally instead. So despite the way the prophets worded it, sin brings its own punishment. (That's why God deems it sin.) If justice requires us to be punished for sin - I say IF - there is no need for God to do it; it happens all by itself. God's purpose is to save us from our self-inflicted misery, not to add to it.
A related argument we hear frequently that also has some truth to it is, "Whom He loves, He chastens," (Heb. 12), and every fruitful branch He prunes, that it may bear more fruit, says Jesus. (John 15:2) The truth in it, of course, is that we cannot grow in the absence of adversity. So God lets us have some. But one may well ask, "Did the 'adversity' have to be so absolutely devastating?" or, if we have lost someone dear, "Did correcting me have to be at the expense of a human life and ruin all my happiness?" We are told suffering is meant to drive us to repentance, but it may as well backfire and drive us away from God — as He surely foreknew it would. So this argument is true but incomplete.
There is a whole category of arguments that follow the same pattern: "God permits evil in order to _________" fill in your favorite Greater Good. "If this evil hadn't happened, then this greater good wouldn't have, either." Again, there's some truth to this: God can and does bring good, even great good, out of evil. But to say God makes good use of evil does *not* mean He is ever, ever complicit in it! No! No, God does not require evil to bring about good, thank you very much. He is perfectly able to do this without any help from the devil. So every answer of this category is at best inadequate.
Judaism confronts the tormenting question of why God permits evil by basically saying, "We do not know and who are we to challenge God?" God replies to Job's challenge:
“Who is this that darkens counsel by words without knowledge?
Prepare yourself like a man;
I will question you, and you make it known to me.
“Where were you when I laid the foundation of the earth?
Tell me, if you have understanding.
Who determined its measurements—surely you know!
Or who stretched the line upon it?
On what were its bases sunk,
or who laid its cornerstone,
when the morning stars sang together
and all the sons of God shouted for joy?
“Or who shut in the sea with doors
when it burst out from the womb,
when I made clouds its garment
and thick darkness its swaddling band,
and prescribed limits for it
and set bars and doors,
and said, ‘Thus far shall you come, and no farther,
and here shall your proud waves be stayed’?"
This rebuke goes on, beautifully poetic, for four chapters!
"Prepare yourself like a man;
I will question you, and you make it known to Me.
Will you even put Me in the wrong?
Will you condemn Me that you may be in the right?
Have you an arm like God,
and can you thunder with a voice like his?"
Etc.
Christianity has another approach to the Problem of Evil. It isn't philosophical; that is, doesn't answer the Why. This is because Christianity isn't a philosophy but a relationship. Its answer is couched in terms of God's relationship with us.
The first point of that relationship is solidarity. God becomes Man. Not temporarily, but permanently; He ascended into heaven in His body. Without ceasing to be truly, fully God, He becomes fully, truly human. He knows, from the inside, what it is for us to live a human life. He steps into our life and shares its temptations and triumphs, joys and sorrows. He hungers, He thirsts, He weeps, and on the Cross, He shares our suffering and sorrow right down to the last, bitter dregs, even the feeling of godforsakenness we sometimes have. He experiences it all, including death. No matter how bitterly we suffer, how crushing our load, how broken-hearted we may be, He is with us through it all, closer to us than we are to our own hearts. He knows firsthand what we are enduring and never deserts us, no matter what, even when we desert Him. Almighty Love always, always enfolds us.
The second point about God's relationship with us is hope. He arose from the dead. This is not a hope that tries to gloss over the deep grief and bereavement we feel when someone we love has died. The loss is real, even though it pertains only to the flesh and not the spirit, and it can be staggering. Nevertheless, Christ arose. Christ conquered death. This is not to deny the fearsome reality that the soul departs from its body and the body decays in the grave. But it is to say neither soul nor body will ever be separated from God, who will raise them both together on the Last Day. The soul shall never die. The body will, but like a seed planted in the ground, it will bring forth a new plant; that is, a new, glorified body like His.
But there's much more to our hope even than this, because Christ's triumph over death is like a deposit you pay when buying a house, as assurance that you will make good on your promise. Our foe's chief weapon had always been death, so in vanquishing death, Christ has disarmed him. (He. 2:14-15) And that disarming or defanging of evil is His deposit or down payment on His pledge ultimately to do away with it altogether. His promise is:
"They shall hunger no more, neither thirst anymore; the sun shall not strike them, nor any scorching heat. For the Lamb in the midst of the throne will be their shepherd, and he will guide them to springs of living water, and God will wipe away every tear from their eyes.” (Re. 7:16-17)
And again:
He will wipe away every tear from their eyes, and death shall be no more, neither shall there be mourning, nor crying, nor pain anymore, for the former things have passed away.” (Rev 21:4)
Why not now, we may ask? Why is He delaying so long? We don't know. Only God knows His reasons.
But that "Why?" turns out not to be the main question after all. The main question is, will we latch on to that "sure and certain " Hope or not? Will we continue to trust God until then, and trust that He is good, or not?