The Response to Psalm 51 is from Hosea 6:6: "I desire steadfast love and not sacrifice." And the verse
continues: "...the knowledge of God rather than burnt offerings." The theme of all three readings is that God looks to the heart, not to external actions. What he wants from us is deep, enduring love and the desire to know him, not just "orthodoxy" or acts of religious observance, no matter how good these are in themselves.
Hosea 6: 1-6 is a call to conversion that tells us two things:
God will without doubt "heal" and "revive" us.
For this to happen we must change our hearts, not just our behavior: "For I desire steadfast love and not sacrifice, the knowledge of God rather than burnt offerings." Hosea's exhortation is: "Let us know, let us strive to know the LORD."
In Luke 18: 9-14 Jesus gives this teaching in the form of a story. What we need to focus on is the contrast in attitude between the Pharisee and the public sinner (tax collectors were thought to be extortionists and collaborators with the Romans).
The attitude of the Pharisee is widespread in the Church today. We find it in those who feel they must defend the Church against the "theologians," the "liberals" and the "lax" Catholics who do not adhere blindly to all the rules and directives that are sent out from various departments in the Vatican, and who do not blindly accept all the current doctrinal rulings of the "magisterium" as representative of the whole teaching of the Church. They are not only "convinced of their own righteousness," but also convinced of their own orthodoxy - so much so that when they listen to teaching and preaching, it is not so much to learn and respond as to check out the orthodoxy of the speaker. They have nothing new to learn, because they have narrowed down their interests to "the answers" that persons in authority (a narrow and misleading definition of the "magisterium" of the Church) have given to current questions without seeing these against the background of the Church's historical and truly universal teaching. Because they reduce the truth to just what they see, they can be convinced that what they see is the whole truth. So they are characteristically deaf to explanations and to answers given to their objections. They listen only to compare what they hear to what they already believe, and to condemn what- ever does not match.
This is the "idolatry of the cut-and-dried" that excludes all personal interaction with the mystery of the living God. It is Phariseeism and a lethal rejection of discipleship.
Initiative: Be a disciple. Learn. Do not judge before you understand.