Don't say, "I will get even for this wrong."
Wait for the Lord to handle the matter.
Someone does something to you...
*Steal your sandwich at lunch
*Spread an ugly rumor about you
*Cut you off when you are driving
*Bump into you in line at the store
**hurts your kid
**causes some thing bad to happen to you (ie; cause you from getting a promotion)
**harms someone you love
Basic human nature is to get back at them. A lot of times our first instinct (to even the most minor offense) is to get some sort of revenge.
Lots of people love to live by the Old Testament "An Eye for an Eye" (Exodus 21:24). That's one verse people can remember.
(They tend to forget about what Jesus said about it...