Matthew 9:13 - Religion with Power or just Form?

Go and learn what this means: 'I desire mercy, not sacrifice.'
Mat 9:13 (NIV)

This is not a declaration on the part of God that he was opposed
to "sacrifices" or "offerings for sin;" for he had appointed and
commanded many, and had therefore expressed his approbation of them. It is
a Hebrew mode of speaking, and means, "I prefer mercy to
sacrifice;" or, "I am more pleased with acts of benevolence and kindness
than with a mere external compliance with the duties of religion."
Mercy here means benevolence or kindness toward others. "Sacrifices"
were offerings made to God on account of sin, or as an expression of
thanksgiving. They were commonly bloody offerings, or animals slain;
signifying that the sinner offering them deserved to die himself, and
pointing to the great sacrifice or offering which Christ was to make for
the sins of the world.... The sense in which our Saviour applies it
is this: "You Pharisees are exceedingly tenacious of the "external"
duties of religion; but God has declared that he prefers benevolence or
mercy to those external duties. It is proper, therefore, that I should
associate with sinners for the purpose of doing them good." (Barnes'
Notes)

Christ's conversing with sinners is here called mercy: to
promote the conversion of souls is the greatest act of mercy imaginable;
it is saving a soul from death, <James 5:20>. (Matthew Henry's
Commentary)

The Pharisees constantly tried to trap Jesus, and they thought
his association with these "low lifes" was the perfect opportunity.
They were more concerned with their own appearance of holiness than
with helping people, with criticism than encouragement, with outward
respectability than practical help. But God is concerned for all people,
including the sinful and hurting ones. The Christian life is not a
popularity contest! Following Jesus' example, we should share the gospel
with the poor, immoral, lonely, and outcast, not just the rich,
moral, popular, and powerful. [Life Application SB]

The Scribes and Pharisees were more concerned with the
preservation of their own holiness than with the helping of another's sin.
They were like doctors who refused to visit the sick lest they should
be injured by some infection. They shrank away in fastidious
disgust from the sinner; they did not want anything to do with people
like that. Essentially their religion was selfish; they were much
more concerned to save their own souls than to save the souls of
others. And they had forgotten that that was the surest way to lose
their own souls. [Barclay Commentary]

The Lord's response demonstrated that His ministry is directed
toward those who realize they have a need: Only sick people need a
doctor. The Pharisees did not think they were sinners (sick) so they
would never have sought out the Lord (the Physician). The Pharisees
always brought the proper sacrifices, but they were totally lacking in
compassion toward sinners. When mercy is lacking, then religious
formalities are meaningless (cf. Hosea 6:6). [Bible Knowledge Commentary]

As used here, "mercy" may be said to stand for character, that
is, for the traits of character that God would have His people
reflect (see on Matt. 19:19; 22:39). Similarly "sacrifice" stands for
the forms of religion, which have an unfortunate tendency to eclipse
practical religion (see 2 Tim. 3:5). In this sense "mercy" represents
righteousness by faith as "sacrifice" does righteousness by works. The forms
of religion without the vital spirit of religion, Christ says, are
worthless. [SDA Commentary]

He presented a pure character as of supreme importance. He
dispensed with all pomp, demanding that faith that works by love and
purifies the soul, as the only qualification required for the kingdom of
heaven. He taught that true religion does not consist in forms or
ceremonies, outward attractions or outward display. FE398

The Jewish leaders looked with pride upon their magnificent
temple, and the imposing rites of their religious service; but justice,
mercy, and the love of God were lacking. The glory of the temple, the
splendor of their service, could not recommend them to God; for that
which alone is of value in His sight they did not offer. They did not
bring Him the sacrifice of a humble and contrite spirit. It is when
the vital principles of the kingdom of God are lost that ceremonies
become multitudinous and extravagant. It is when the character building
is neglected, when the adornment of the soul is lacking, when the
simplicity of godliness is lost sight of, that pride and love of display
demand magnificent church edifices, splendid adornings, and imposing
ceremonials. In all this God is not honored. A fashionable religion that
consists of ceremonies, pretense, and display, is not acceptable to Him.
Its services call forth no response from the heavenly messengers.
COL297,8

When Jesus uses "call," kalesai, it has the force of "invite."
His enigmatic saying makes an important point. First-century Jews
expected the Messiah to appear and, after purging Israel of sinners,
establish an earthly kingdom for the righteous. Here Jesus reminds us that
His mission is one of grace; He has come to pursue the lost. Those
who classify themselves as "the righteous" not only have
misunderstood His mission, but have placed themselves outside the circle of
those who stand in need of God's grace. No one is more difficult to
reach with the Gospel message than the person convinced its Good News
is desperately needed by someone else. [Victor Bible Background
Commentary]

Those who are sure that they are righteous can't be saved,
because the first step in following Jesus is acknowledging our need and
admitting that we don't have all the answers. As long as people insist on
their own qualifications as good enough to stand before God, they are
cut off from hope. [Life Application SB]

Jesus did not come to invite people who are so self-satisfied
that they are convinced they do not need anyone's help; I came to
invite people who are very conscious of their sin and desperately aware
of their need for a saviour." He was saying, "It is only those who
know how much they need me who can accept my invitation.' [Barclay
Commentary]

Here is the essence of Christ's call to salvation. In great
mercy He calls needy sinners to refuse to rely on their own
righteousness and to humbly learn from Him. Those who respond positively to
Christ's call through repentance and faith find salvation. [Disciple SB]

Some folks scoff at Christianity as "pie in the sky by and by."
Others just shrug, and say they'll wait and find out after they die.
When Jesus was here He made sure no one had to wait to see. He
told a paralytic, "Your sins are forgiven" (vv. 1-8). When some
bystanders were upset by this claim, He offered proof. "So that you may
know the Son of man has authority on earth to forgive sins." He told
the paralyzed man, "Get up, take your mat and go home."
When the man stood up, and walked, the authority of Jesus was
proved. The men of that day knew that Jesus could forgive sins.
But how about our day? The next story is for us. It's the story
of a man named Matthew who sat at a tax booth (vv. 9-13). In the
first century such men were scorned as sinners, and most did extort
more money than was due. Jesus came to Matthew's booth and told him,
"Follow Me." And Matthew got up and followed.
Matthew the tax collector. Matthew, whose friends were the
outcasts of pious society, became a follower of Jesus.
This is the proof we see all around us of the fact that when
Jesus says, "Your sins are forgiven," our sins truly are. Forgiveness
makes just as dramatic a change in the moral life of the believer as
Jesus' healing did in the frozen limbs of the paralytic.
A world that wants proof that Jesus saves can find it in the
transformed lives of those who have accepted Him as Saviour. [The 365-Day
Devotional Commentary]