Henri Nouwen on the older son of Luke 15:
The more I reflect on the elder son in me, the more I realize how deeply rooted this form of lostness really is and how hard it is to return home from there. Returning home from a lustful escapade seems so much easier than returning home from a cold anger that has rooted itself in the deepest corners of my being. My resentment is not something that can be easily distinguished and dealt with rationally. It is far more pernicious: something that has attached itself to the underside of my virtue.
--The Return of the Prodigal Son, p. 75