If you want a very satisfying and hopeful answer to the problem of evil, read these two pages:
http://www.watchtower.org/e/20010515/article_01.htm and
http://www.watchtower.org/e/20010515/article_02.htm. Actually the first page is just an introduction, you can skip it.
I'll give you some highlights (about 1/3 of the original page):
When God created the first human, he produced more than just a body with a brain. Further, God did not create Adam and Eve to be mindless robots. He implanted in them the faculty of
free will. And that was a fine gift, for "God saw everything he had made and, look! it was very good." (Genesis 1:31)
However, was the fine gift of free will to be used without limits? In directions given to early Christians, God's Word answers: "Be as free people, and yet holding your freedom, not as a blind for badness, but as slaves of God." (1 Peter 2:16) For the common good, there must be boundaries.
Humans were not created to be independent of God. God made mankind subject to his physical laws, such as the law of gravity. Similarly, he made humans to be subject to his moral laws, which are designed to result in a harmonious society. For good reason, then, God's Word urges: "Trust in Jehovah with all your heart and do not lean upon your own understanding."—Proverbs 3:5.
What went wrong? God gave our first parents, Adam and Eve, a perfect start. Of their own free will, they stepped outside the boundaries of his laws. (Genesis, chapter 3) "Through one man [Adam] sin entered into the world and death through sin, and thus death spread to all men because they had all sinned."—Romans 5:12.
The main issue - sovereignty. When Adam and Eve rebelled against God, they challenged his sovereignty, that is, his right to rule. Jehovah could have destroyed them and started over with another couple, but that would not have settled the issue of whose rulership is right and best for people. Granted time to develop their societies according to their own ideas, humans would demonstrate beyond any doubt whether rulership independent from God could ever be successful.
God will soon intervene in human affairs. The vindication of Jehovah God's sovereignty by means of the heavenly Kingdom is the Bible's theme. Jesus made this his foremost teaching. He said: "This good news of the kingdom will be preached in all the inhabited earth for a witness to all the nations; and then the end will come."—Matthew 24:14.
When God's rulership replaces man's rule, who will survive and who will not? At Proverbs 2:21, 22, we are assured: "The upright [who uphold God's rule] are the ones that will reside in the earth, and the blameless are the ones that will be left over in it. As regards the wicked [who do not uphold God's rule], they will be cut off from the very earth."
A marvelous new world. Marvelous physical benefits will flow to obedient humans living in God's new world. There will be a canceling out of all the bad consequences of rebellion against God's rule. Imperfection, sickness, old age, and death will be things of the past. The Bible assures us: "No resident will say: 'I am sick.'" Moreover, the Scriptures promise: "At that time the eyes of the blind ones will be opened, and the very ears of the deaf ones will be unstopped. At that time the lame one will climb up just as a stag does, and the tongue of the speechless one will cry out in gladness." (Isaiah 33:24; 35:5, 6) What a thrill it will be to enjoy vibrant health every day—forever!
What about the billions of people who have died? Those in God's memory will be brought back to life, for "there is going to be a resurrection of both the righteous and the unrighteous." (Acts 24:15) Yes, the dead will be restored to life. They will be taught the wonderful truths regarding God's rulership and be given the opportunity to live forever in Paradise.—John 5:28, 29.
So........... I couldn't have said it better. Conclusion: evil is tolerated for a time, to prove once and for all that people are better off living with God. The world we live in now is not what God wants and He will change it soon. All suffering will be compensated for, even death.