In the gospel for today, the Lord reminds us that we live from the inside out. That is a hard lesson for us to accept. For good or bad, we tend to obsess on externals: what we say, what we do, and how we are perceived. We try to change and manage these externals. Sometimes we can pull it off. Some people are very effective at it. Basically in our society the ability to manage externals has a lot to do with success.
Many of us are not so good at managing externals. We become frustrated because we cannot manage them. The Lord is giving us other counsel. We should first be concerned with what is inside. Do I really love the truth? Do I really want the good? Am I willing to face the selfishness inside of me? Goodness will flow from a heart in love with the One who good. Reverence will flow from the heart that is in wonder of the creator. Truth will flow from the lips of one who knows the One who is true.
Externals are important as the overflow of a heart transformed on the inside. This is called integrity. This is why there really is no reasonable separation between public and private life. We may be able to do good things for a time as an external show, but we need to be more than good performers. Surely we want to be more.