While Christians look forward to that day with hope when, once for all , evil will be banished, never again to trouble God's creation, many other people reject God and the gospel precisely because of evil in the world.
The scene of God ultimately destroying Satan and his hosts (Rev. 20:1-20) brings a joyful conclusion not only to the revelation, but to the entire Bible.
How come a God who is good and loving allow evil and suffering in His world?
The bible teaches that God did not create evil. The world He made was utterly good (Gen. 1:31). But people themselves turned against God, using His gift of free will to rebel against Him. With that moral rebellion, the perfection of God's world came tumbling down and people began to suffer.. The Bible also claims that behind human wickedness lies a great outside influence -Satan. This fallen angel hates God and everything to do with Him. He is out to destroy both humanity and the environment and does everything he can to attack God and His purposes. He promotes much of the evil and suffering that we see.
Even though God did not create evil, nor does He will it, He nevertheless uses it to accomplish His purposes. For instance, God sometimes uses pain to draw people to Himself, especially when they otherwise would not respond to Him. Likewise, the struggle against evil has led many people to strive for good, producing such admirable traits as courage, endurance, self-sacrifice, and compassion.
Why then, if God is all powerful, does He not remove evil from the world?
This question assumes that He has done nothing. But in fact, He has. First, God Himself came into this world, with all its sorrow and pain, and lived as a man. Jesus knew poverty, thirst, hunger, injustice, physical abuse, heartbreak, and betrayal. He ended his life in excruciating pain. So God certainly understands our condition. He has personally experienced it. In the process, God dealt with the problem of evil at its root. On the cross, Jesus took on Himself the wickedness of every person who has ever lived in order to do away with it. Christ broke the grip of evil that holds the world captive. Already we can see among God's people a glimpse of the new life that He has brought about (Rom. 8: 4, 11).
This brings us to God's final solution to evil, which John describes in Revelation 20. In the end, God will triumph by doing away with evil and those who promote it. He will restore His creation and his creatures to their original purpose, to the original relationship they enjoy with Him. Suffering will be but a memory. Goodness, justice, and peace will characterize the moral climate of God's new heaven and earth.