A spirit of self-assurance is a gospel-denying, self-deceiving, friendship-destroying mentality. It is natural to say to ourselves, “I’m doing my part. They should be grateful.” It is supernatural to say to ourselves, “I place myself under the judgment of the Word of God. I humble myself. Even if the other person is wrong, that gives me no right to assert myself. No matter what the other person does, no matter how much I am misunderstood and misjudged, I will remain in the fear of the Lord, I will entrust myself to God.” True friendship thrives when, before God, each one is more aware of his debts than his rights.
~Ray Ortlund, from the Gospel Coalition Blog