10 And as Jesus reclined at table in the house, behold, many tax collectors and sinners came and were reclining with Jesus and his disciples. 11 And when the Pharisees saw this, they said to his disciples, “Why does your teacher eat with tax collectors and sinners?” 12 But when he heard it, he said, “Those who are well have no need of a physician, but those who are sick. 13 Go and learn what this means, ‘I desire mercy, and not sacrifice.’ For I came not to call the righteous, but sinners.” Matthew 9:10-13, English Standard Version
I've been reading Unclean: Meditations on Purity, Hospitality, and Mortality, by Richard Beck of Abilene Christian University, and he uses verse 13 as a theme throughout the book to demonstrate the conscious (and more often, subconscious) boundaries we have in our minds, and what we do with them. As Beck is an experimental psychologist, and not a theologian, this book addresses issues in the Church from a standpoint of attitudes and actions in missionality, and not as doctrine or dogma.
Using verse 13 of Matthew 9, Beck makes the case that the deeper psychological meaning of "sacrifice" here is not so much about offering sacrifice at the temple as it is about how the Pharisees, and we as Church members today, can sacrifice people to be excluded from the Church due to their status as "sinners" or "unclean." Without an in-depth recap of Beck's argument, I think we can extend his ideas from the Church level to the level of our personal attitudes and relationships.