"We have all become like one who is unclean, and all our righteous deeds are like a polluted garment. We all fade like a leaf, and our iniquities, like the wind, take us away." — Isaiah 64:6, ESV
When I begin to get arrogant in my self-righteousness, this verse brings me back to reality. Quickly. The writers of most translations are very polite with their translation of "polluted gardments" and "filthy rags." In the original language, it actually says that our righteous deeds are like used menstrual rags. God just has a way with words,doesn't he?
When we begin to think that we really are that impressive and the growth that we have seen in ourselves over the years is because of our own abilities and personal wisdom, we need to be brought back to this truth: without Jesus we have nothing. No amount of good things will measure up to God's perfect standard. For Christians, we do not work to gain heaven but rather because we already have it. We don't do good things to be saved but rather good things spring from our lives proving that we have been saved.
So if you've become arrogant in self-righteousness and irritated by those who don't know Christ, remember what your righteous deeds look like when compared to the holy and perfect standard of God. And then thank God for his grace. And then share that grace with others.