Although evil is here and it is real, it is also temporary. Evil will eventually be destroyed. This is the hope that the believer has. Paradise lost will be paradise regained. God will right every wrong and put away evil once for all, in His time.
Christians have a justification for fighting evil, immorality and corruption.
The world was not designed with evil in mind and the believer has a real basis for fighting social ills. He is not following the belief that whatever is, is right. The Christian does not condone wrongdoing by claiming it is God's world, neither does he assume that everything that happens is agreed to by God. God does not desire evil nor does he ever condone it. He hates evil, and the Christian also is not only to despise evil, they are obligated to do something about it.