Judge not, that you may not be judged,  For with what judgment you judge, you shall be judged: and with what measure you mete, it shall be measured to you again.  And why seest thou the mote that is in thy brother's eye; and seest not the beam that is in thy own eye?  Or how sayest thou to thy brother: Let me cast the mote out of thy eye; and behold a beam is in thy own eye?  Thou hypocrite, cast out first the beam in thy own eye, and then shalt thou see to cast out the mote out of thy brother's eye.
Sometimes in life we must look not just at what Sacred Scripture says, but also why and how. When we feel slighted or hurt, this is often the passage from the Sermon on the Mount which is brought out. I know that my aunt was famous for this, as was my grandmother. What we must realize though, is that this passage works both ways. While we might feel slighted by another, we must be EXTREMELY careful not to confuse right action with righteous indignation. I know that I am guilty of that from time to time. I know that it can certainly be a dangerous trap to fall into, because I've fallen into and I've watched family and friends fall into the same trap.
Yes, there are things which offend the senses. Yes, there are actions which offend the person. We are fallen people and we do not have a monopoly on what is right and what is wrong. However, to bring forth Sacred Scripture and apply it where it is not necessarily applicable is not in anyone's best judgment. And what normally follows is an explosion of pride. Something along the lines of, "Well, I can't be wrong...so and so is wrong." "I was offended because of X."
When in all reality, if one does a TRUE examination of his own conscience, he will find that his actions leading up to the event are just as caustic and detrimental as any other. As time passes, we must realize that we are human. We must realize that we do make mistakes. We must realize that one of the greatest gifts that God gives is the ability to forgive. He forgives through Penance. We forgive through our own selfless action and attributes toward others.
Like I said, my grandmother was notorious for using this line when she felt slighted. But does she have the right, based upon the two-way nature of what Christ is saying to follow through on that. Or should she have trusted that it would be neither her or the person she felt slighted who would remove the splinter/plank, but rather that it would be God.
A little later on in Chapter 7, Christ says and St. Matthew follows;
 And every one that heareth these my words, and doth them not, shall be like a foolish man that built his house upon the sand,  And the rain fell, and the floods came, and the winds blew, and they beat upon that house, and it fell, and great was the fall thereof.  And it came to pass when Jesus had fully ended these words, the people were in admiration at his doctrine.  For he was teaching them as one having power, and not as the scribes and Pharisees.
On both sides of this coin we find that the only One who we should be attributing the words to as far as judgment is Christ. However, the forgiveness is to be given and freely accepted by all, who offer it and receive it. Please understand, we are not the purveyors of judgment and justice, Christ Jesus is. We are merely partakers. We don't judge. We don't presume to judge. We presume to do what is necessary to love, honor and respect our fellow man, REGARDLESS of our personal feelings of slightedness. If God forgives and gives absolution for the most serious and the most petty sin, then should we not do the same?