1. Without an absolute standard of "good" there can be no such thing as "evil" in the world. Biblically speaking, something is evil only because it is a contradiction of the absolutely good character of God. For the unbeliever to raise the "problem" of evil, without an absolute standard of good as their reference point, is foolishness. Before the unbeliever can even raise the problem of evil, they must first give an account for how they can account for good and evil at all!
2. God is not a passive bystander who carelessly watches the evil that occurs in this world from a distance. He is not like the selfish king who sits idly by in his castle feasting while the people of his land starve to death, feeling nothing and caring nothing for their plight. Part of the glory of the Biblical perspective of evil is that God himself has come down into this world and experienced the evil of it firsthand in the person of the God-man, the Lord Jesus Christ. For someone to say that "God doesn't know what I've been through" is to deny the reality of the incarnation.
3. There will be a day when every wrong in this world is put right; a day when every evil will be punished to the full extent of justice. There will not be one sin that is left unpunished, not one "little white lie" that is not called to account. (In fact, it seems right Biblically to say that that punishment often times begins even in this life.) The doctrine of hell is the answer to the oft heard inquiry of "Why doesn't God do something about the evil in the world?" In fact, he has done, is doing, and will "do something". The person who brings this particular objection up is often the unbeliever who seeks to ridicule God by implying that He just allows evil to go on in this world without doing anything about it. But what they are really asking for (unwittingly) is the Biblical reality of hell. In addition, this statement from them confirms the existence of "the law written on the heart," and the inherent sense of righteousness and justice that every person, created in the image of God, possesses.
4. When it comes right down to it, the "problem" of evil is something that we all have played a part in. This was well-put by author G.K. Chesterton in reply to an invitation from The Times for several well-known authors to write essays on the topic of "What's Wrong With the World?" Chesterton's reply was brief, but profound:
Dear Sirs,In other words, the world is not the way it is because of a few bad people like Stalin, Hitler, Pol Pot and Mao Zedong. The world is the way it is because it is made up of multitudes of people just like us. There is deep-seated evil that resides in the heart of every fallen son of Adam. Sometimes that evil will manifest itself in greater ways in the lives of some people more than others. Nevertheless, at the core of every human being ever born is a corrupt, polluted heart that is capable of unspeakable evil. It's easy for someone to survey the world scene and to piously bemoan all of the evil present in it, while at the same time being utterly blind to the blackness of their own heart. Such people are nothing more than hypocrites who love to cast blame on God, while being blind to the fact that they themselves are part of the problem.
I am.
Sincerely yours,
G. K. Chesterton
But the glory of the gospel of Jesus Christ is that God is actually able to take out someone's evil, corrupt heart, and give them a new heart; a heart that loves God, righteousness and truth. May the Lord open the eyes of anyone reading these lines who is still hiding behind their filthy rags of self-righteousness, while inside they are full of dead men's bones and all manner of corruption. It's only when we are honest enough to admit that we are part of the problem, that God will begin to work in us in order to make us part of the solution.