Grinding our gears
Have you ever been hurt? Of course you have. Stolen from? Royally taken advantage of? Shunned, invalidated, hated? I think (but wouldn't hope) we all have. It lends flavor and body to this thing called life. Part of life then is learning how to roll with those punches. How to continue being yourself in spite of feeling no reason to. And that's the thing to which those barbs, those "fiery darts of the wicked" (Ephesians 6:16) are aimed. The sanctity of your person before God. I suppose, then, that the "revenge complex" is born out of an inverted "do unto others" paradigm? I could be wrong, but think about the basis for revenge to those who've wronged you. I want to make them feel what they forced me to.
"Dearly beloved, avenge not yourselves, but rather give place unto wrath: for it is written, Vengeance is mine; I will repay, saith the Lord." (Romans 12:19)
Probably the oft-quotedest verse on vengeance. The simple answer is that any wrong done to us is ultimately aimed at the God Whom we represent, Whom we symbolize. Yes, "represent" is a fuller description of that which we're on earth to do. I like the connotation of "symbolize" though. Either way, the closer we walk with God, the more riled will people get who don't feel like walking with (or acknowledging) God, at all. Because we represent God whether we realize it or not. If we don't realize it though, that might play in to what makes someone think they can hurt us and get away with it, in the first place. Paul continues: "Therefore if thine enemy hunger, feed him; if he thirst, give him drink: for in so doing thou shalt heap coals of fire on his head." (verse 20) While that was written under the Old Covenant, I can't say that that construct--of reaping "whatsoever a man soweth." (Galatians 6:7)--isn't still out there. And working.
"But a certain Samaritan, as he journeyed, came where he was: and when he saw him, he had compassion on him, And went to him, and bound up his wounds, pouring in oil and wine, and set him on his own beast, and brought him to an inn, and took care of him. And on the morrow when he departed, he took out two pence, and gave them to the host, and said unto him, Take care of him; and whatsoever thou spendest more, when I come again, I will repay thee." (Luke 10:33-35)
The story of the good Samaritan is about Christ and us. We were beat up and left for dead and Jesus found us "half dead". Nothing is again mentioned of the thieves who "stripped him of his raiment, and wounded him, and departed". Because it's between God and us. And God and them.
Pouring in oil
Life is a funny thing. God started it. He originated it, He created it. It all ultimately flows back to Him. Without sounding fanatical, it's Him who has given us the privelege of living. This is why it says "vengeance is mine". Because, on this level, we are merely containers. God wants to do things on this earth. Taking things personally, then, is foolish, in spite of the fact that it hurts so much. If we choose to look at it in light of Jesus and sharing in "the afflictions of Christ" (Colossians 1:24), it lends the correct perspective to our pain and misery. So forgive your offenders. The wheels of vengeance began turning of their own accord when they hurt you. They might turn slow, but the effects will come full circle. Paul said that doing good to those who hurt you will "heap coals of fire on [their] head". And elsewhere, speaking of "Alexander the coppersmith", who, he says "did me much evil: the Lord reward him according to his works." (2 Timothy 4:14) Without a full and radical heart-change brought about by humbling oneself under the Lord and receiving His forgiveness one-on-one, those "engines of vengeance" will continue running and the offender will end up reaping what they sowed. The good that Paul speaks of which in turn causes "coals of fire" to rain on our "enemy" doesn't seem to do anything to alleviate that which our enemy had coming to them.
"Woe to thee that spoilest, and thou wast not spoiled; and dealest treacherously, and they dealt not treacherously with thee! when thou shalt cease to spoil, thou shalt be spoiled; and when thou shalt make an end to deal treacherously, they shall deal treacherously with thee." (Isaiah 33:1)
The complexity of revenge
And what about the real thick and heavy stuff? The subtle and slow-burning lies and things that continue for days and days and years undetected? The things that aren't just designed to hurt once and that's it? We forgive these things too, obviously. Thing is though, the deeper we've been hurt, the more we'll have to wait on God to ensure that what comes out then, is not based on the pain we received from them, but on the grace and mercy that we in turn receive from God. Hell is a real place.
"But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you. That ye may be the children of your Father which is in Heaven: for he maketh His sun to rise on the evil and the good, and sendeth rain on the just and on the unjust." (Matthew 5:44-45)