The people were astonished at his teaching,
for he taught them as one having authority and not as the scribes.
In what did this authority consist? How was it so different from other teachings they heard as to be astonishing? One commentator named Theophylact suggested that "Christ taught them by rebuke, not by flattery as did the Pharisees". We certainly recognize that was in fact the case. Jesus never held back the truth for the sake of his popularity.
Teacher, we know that you are true and do not care about anyone’s opinion. For you are not swayed by appearances, but truly teach the way of God (see Mark 12:14).
Those who genuinely 'tell it like it is' do speak with a greater authority than those who do not. Yet, aside from Jesus, teachers always have some regard for the opinions of others. We don't say enough or we say too much because of the impression we want to make. Jesus alone was concerned entirely with the truth, knowing that in the truth alone could his hearers find the good purpose for which they were made.
The authority of Jesus was not something he had to document with citations and sources outside of himself. He did reference Scriptures, was consistent with it, and wanted the people to realize that he was indeed its fulfillment. But did not need that as a basis for the things he would teach. Hence in the Sermon on the Mount we read, "It was said to them of old time, but I say unto you" (see Matthew 5:27). The boldness of this authority was so great as to be brazen and blasphemous for anyone other than the Son of God. It was only natural that for those who did not yet accept who he was his words would rub them the wrong way. But his words themselves offered the freedom that comes to those who believe in him (see John 1:12)
He taught them also in power, transforming men to good, and He threatened punishment to those who did not believe on Him - Theophylact
The authority of the words of Jesus went beyond their cognitive content. His words themselves had power to transform. Those whom he said were healed were in fact healed. He did not need to recite lengthy incantations as did most exorcists in his day. His simple proclaiming that it was so made it so. It was the same when he rebuked the storms. The word he spoke was the same word that was spoken to create the world. He was the 'Let it be' by which all things were made. And his voice continued to have that same power when, through the incarnation, he spoke it with a human voice.
Jesus rebuked him and said,
“Quiet! Come out of him!”
The one speaking was in fact the very one whom the Israelites were afraid to hear, so great and imposing was the authority, the truth, the holiness of the one who spoke
‘Let us not again hear the voice of the LORD, our God,
nor see this great fire any more, lest we die.’
Fortunately, in Jesus the words spoken did not bring death, but healed and gave life. We were always meant to hear these words, but sin had rendered us unable to receive the promises they were meant to convey. The way that God chose to repair this in us was by not by silence, but by speaking even more clearly.
but in these last days he has spoken to us by his Son, whom he appointed the heir of all things, through whom also he created the world (see Hebrews 1:2).
When Jesus speaks, just as those possessed by demons found freedom, just as the storms that threatened his disciples were stilled, so too for us now, his words transform. By the power of his words we no longer need regard the intentions of God with terror, but rather with awe and holy fear. Rather than God speaking down to a degenerate and broken people, who would have no recourse but the terror of slaves, his words raise us up, making us sons and daughters, enabling us to delight in the word of the Father.
Rather than "a blazing fire and darkness and gloom and a tempest and the sound of a trumpet and a voice whose words made the hearers beg that no further messages be spoken to them" (see Hebrews 12:18-19) by the authority of the word of Jesus, "you have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, and to innumerable angels in festal gathering, and to the assembly of the firstborn who are enrolled in heaven, and to God, the judge of all, and to the spirits of the righteous made perfect, and to Jesus, the mediator of a new covenant, and to the sprinkled blood that speaks a better word than the blood of Abel" (see Hebrews 12:22-24).
By the authority of Jesus we can replace worldly anxiety and be anxious instead about the things of the Lord, how we may please the Lord, regardless of our station in life. This same authority is given to his Church to set right the things of this world which are still under the sway of darkness. It is given to families. It is indeed given to each believer.
To everyone who conquers and continues to do my works to the end,
I will give authority over the nations (see Revelation 2:26-27)
The voice speaking can change our hearts if we do not harden them. Our choice, our prayer and plea, should be that we be open to listen and receive the authority of Jesus who himself can transform and set us free.