Do not let evil defeat you, but conquer evil with goodness. Romans 12:21
Paul stresses internal attitudes and dispositions when he talks about Christian life on love. To conquer evil is hold to whatever is good. Bless those who persecute you; bless and do not wish evil on anyone. Do not return evil for evil is a demanding commandment of forgiveness so often formulated by Jesus.
We must discern the will of God, what is good, what pleases and what is perfect. God demands not only good deeds but still more a complete transformation of our person. First of all we must acquire new criteria and a new understanding of our existence. A constant effort to learn, to meditate and to understand the will of God in everything that happens to us. Have hope in the Lord and be cheerful. Be patient in trials and pray constantly.
Deep are the riches, the wisdom and knowledge of God. His decisions cannot be explained, nor his ways understood! It is false wisdom that which advises us to return evil for evil, mean behavior for mean behavior, a tooth for a tooth and an eye for an eye.
The Christian is asked, beloved, do not avenge yourselves, but let God be the one who punishes, as scripture says : Vengeance is mine, I will repay, says the Lord. And it adds : If your enemy is hungry, feed him; if he is thirsty, give him to drink; by doing this you will heap burning coals upon his head. (Romans 12:19-20). A best way of conquering evil with goodness stressed by Paul who presented himself as the public announcer of the liberating message given to all humankind.
Darkness can only be scattered by light, hatred can only be conquered by love.