Blessed are the peacemakers, for
they shall be call sons of God.
Matthew 5:9
If possible, so far as it depends on
you, be at peace with all men.
Romans 12:18
Therefore, to one who knows the
right thing to do and does not do it,
to him it is sin.
James 4:17
There is much that goes in to being a peacemaker. To simplify it and to boil it down to its essence, it is doing what you must do to be at peace as long as it doesn't violate Scripture or your conscience. It is not going with your flesh, it is holding your tongue, it is not taking into account a wrong suffered, it is taking the blow (physical or otherwise), it is not being vindictive, it is having your vanity stepped on, it is having your feathers ruffled, it is suffering for righteousness sake. It is doing all of these without striking back or standing up for yourself or lashing out.
There are daily situations with family, friends, co-workers, vendors, other drivers, and a myriad of other scenarios where we must do the right thing and be the peacemaker. It will be up to us to bring peace, or to maintain peace, or simply to take the short end of the stick so that peace will reign. When we do that we are blessed. When we do that we bring glory to God. When we do that we are being like Christ who took the blows (physically and verbally) from the very ones whom He came to save.
So, let us not stand up for ourselves, but stand up for Him in keeping peace and making peace.