Be not overcome of evil, but overcome evil with good. (KJV) ( Romans 12:21 )
How can evil conquer us? It begins in our mind. Anger has a way of stewing inside and then it finally erupts. Quick judgements of others begins as a seed in our thoughts that grows into distaste for another.
Envy and jealousy begin in the mind as well. This passage tells us the key to overcoming evil is by doing good. Doing good comes from a thought but are acted on.
If you feel your thoughts beginning to be critical, angry, or envious, stop them by responding with a loving action. You can conquer everything with good.