There can be no evil in this world, or in the universe, if there is no God who created this universe and life in our world.
Why not? Because how can the natural world hold us responsible for moral actions that are evil? We are all subject to the laws of physics, but we have no moral obligation to them. Even atheist Richard Dawkins admits that as a basis for morality “nature is not on our side.” If individuals could choose their own rules, social harmony would be impossible as nobody would have the right to say that anyone else was wrong. And how can we be sure that public opinion is any better than private opinion? Nobody could say anything was either moral or immoral, right or wrong, good or evil.
A godless universe is morally neutral. Only God can determine that which is good and that which is evil. And evil is that which takes God's good gifts and tries to turn them into ammunition against God.
Conscience’s authority demands a basis that is transcendent, perfect, unchanging and personal – and God is all four. He has given us a conscience which we either become sensitive to and follow (seeking the opposite of evil) or which we sear as with a branding iron, and end up doing evil, but we become so evil we don't even admit we are being evil. We have thousands of years of history to show us evil people doing evil things. To say there is no evil in the world is to deny the whole course of human history.