"All the religious world is boasting of righteousness: it is the doctrine of the devil to retard the human mind, and hinder our progress, by filling us with self-righteousness. The nearer we get to our heavenly Father, the more we are disposed to look with compassion on perishing souls; we feel that we want to take them upon our shoulders, and cast their sins behind our backs. My talk is intended for all this society; if you would have God have mercy on you, have mercy on one another...
"We are full of selfishness; the devil flatters us that we are very righteous, when we are feeding on the faults of others. We can only live by worshiping our God; all must do it for themselves; none can do it for another. How mild the Savior dealt with Peter, saying, "When thou art converted, strengthen thy brethren." At another time, He said to him, "Lovest thou me?" and having received Peter's reply, He said, "Feed my sheep." If the sisters loved the Lord, let them feed the sheep, and not destroy them. How oft have wise men and women sought to dictate [insert a leader's name here] by saying, "O, if I were [that person], I would do this and that;" but if they were in [that person]'s shoes they would find that men or women could not be compelled into the kingdom of God, but must be dealt with in long-suffering, and at last we shall save them. The way to keep all the Saints together, and keep the work rolling, is to wait with all long-suffering, till God shall bring such characters to justice. There should be no license for sin, but mercy should go hand in hand with reproof."
~Joseph Smith in an address to the Relief Society, The History of the Church, Vol 5, pp 23-24
"Self-righteousness is a form of egotism that breeds intolerance and impatience. Lack of empathy is its major symptom. Since self-righteousness is an unhealthy inner pride, the cure for it is honest humility. Jesus, the most righteous of all, was the perfect example of humility. He said, 'I am meek and lowly in heart.' (Matt. 11:29.)"
~Richard Lloyd Anderson, "Parables of Mercy"
I believe this is something it is vital that I be aware of, whichever side of whatever religious or ecclesiastical issue I am on. And I believe that we all tend to quickly recognize failure to do this on the part of those who disagree with us or who fail to do what we hope they will do, but that most of us, including me, have a harder time seeing it in ourselves or in those with whom we agree.