In today’s gospel reading, Jesus cites an Old Testament teaching that God desires mercy and not sacrifice. This teaching is found in Hosea 6.6.
But wait a second, I thought God commanded sacrifice in the Old Testament. Indeed he did. A significant portion of the Book of Leviticus deals with regulations concerning sacrifice.
Thus, there is nothing wrong with sacrifice per se. The problem arises when sacrifice is divorced from mercy and goodness.
In the story in the gospel the religious leaders had placed the observance of religious rules above the well being of people. This serves as a warning for us.
The ideal is a life where ritual and mercy are working in conjunction. We allow the Holy Spirit to work in us at the times of our religious observance to make us more merciful people.
But, when situations arise where perhaps someone has violated a ritual observance, or as in the case of the gospel reading, our own conceptions about what religious observance requires, we should always err on the side of charity.