“Go and learn what this saying means: ‘I want mercy and not sacrifice.’ For I did not come to call the righteous, but sinners.”
Jesus called people who were aware of their need for forgiveness. Those who considered themselves righteous would not listen.
Some use the ritual of religion to prove their worthiness before God. Jesus rejected justification on this basis. Selective obedience (sacrifice but not mercy) is no obedience at all.