Conquer evil by doing good

The greatest difficulty and danger in fighting against the works of evil is that, more often than sometimes, the same evil spirit we are fighting against could also be at work within us. And if we are not careful to examine our selves first and seek the guidance of God's Spirit, our actions will tend to be evil inspired and we end up combating evil works with evil means -- resulting in an even worse outcome.

Don’t let evil conquer you, but conquer evil by doing good. (Romans 12:21)