Take comfort in the fact that God will not let those who do evil go unpunished. He will repay them, we are right to be angry when we see wickedness perpetrated in the world, righteous anger is justified, yet we must allow God to repay those who do the deeds of wickedness. Look to the psalms of David, time after time he calls on the Lord to avenge him, and to take vengeance on those who do wrong. Our job is to love our enemies and leave the vengeance in the Lord's hands.
Leviticus 19:18
18 ‘You shall not take vengeance, nor bear any grudge against the sons of your people, but you shall love your neighbor as yourself; I am the Lord.
Romans 12:17-21
17 Never pay back evil for evil to anyone. Respect what is right in the sight of all men.
18 If possible, so far as it depends on you, be at peace with all men.
19 Never take your own revenge, beloved, but leave room for the wrath of God, for it is written, “Vengeance is Mine, I will repay,” says the Lord.
20 “But if your enemy is hungry, feed him, and if he is thirsty, give him a drink; for in so doing you will heap burning coals on his head.”
21 Do not be overcome by evil, but overcome evil with good.
Matthew 5:44-45
44 “But I say to you, love your enemies and pray for those who persecute you,
45 so that you may be sons of your Father who is in heaven; for He causes His sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous.
RT