Prov. 16:32
Ecc. 7:9 Do not be quickly provoked in your spirit, for anger resides in the lap of fools.
Eph. 4:26 "In your anger do not sin": Do not let the sun go down while you are still angry,

When someone is mean to us God doesn't want us to be mean back.

Rom. 12:17

He wants us to exercise the spirit of self-control.

Rom. 12:21

Sometimes it works to be nice to the person who is being mean to us.

Prov. 15:1

Sometimes we have to avoid people who are mean.

Rom. 16:17

But we should always pray for them.

Luke 6:28 bless those who curse you, pray for those who mistreat you.

Biblical Examples Of Self-control

Daniel is one of many good examples from the Bible of a man who was self-controlled.  He had many opportunities to act in a disorderly or impatient way, but he always showed self-control.  When he was a young man he could have eaten like a glutton on the king's food, but he was self-controlled and followed the Law of Moses.  Because of his stand for what he believed in he and his friends were put into service to the king himself.

Dan. 1:19-20   The king talked with them, and he found none equal to Daniel, Hananiah, Mishael and Azariah; so they entered the king's service. In every matter of wisdom and understanding about which the king questioned them, he found them ten times better than all the magicians and enchanters in his whole kingdom.

When Nebuchadnezzar asked Daniel to interpret his dreams, Daniel never took personal credit for the interpretations but always gave the full glory to God. 

Dan. 2:27-28   Daniel replied, "No wise man, enchanter, magician or diviner can explain to the king the mystery he has asked about, but there is a God in heaven who reveals mysteries. He has shown King Nebuchadnezzar what will happen in days to come.

Later in the kingdom of Darius the administrators and the satraps devised a plot to have Daniel killed by having Darius sign a law that prevented anyone from praying to any other god or man except himself for thirty days.  Daniel could have become angry and gone to the king, but instead he continued his daily prayers for Israel. 

Daniel 6:10-11   Now when Daniel learned that the decree had been published, he went home to his upstairs room where the windows opened towards Jerusalem. Three times a day he got down on his knees and prayed,