And they went into Capernaum; and straightway on the sabbath day he entered into the synagogue, and taught. And they were astonished at his doctrine: for he taught them as one that had authority, and not as the scribes. And there was in their synagogue a man with an unclean spirit; and he cried out, Saying, Let us alone; what have we to do with thee, thou Jesus of Nazareth? art thou come to destroy us? I know thee who thou art, the Holy One of God. Mark 1:21-24

The New Covenant is now coming, Jesus is about to demonstrate the power and authority of the New Covenant, as it is a Better Covenant made with Better Promises (Hebrews 8:6) When Jesus began preaching in the synagogue, they were amazed at his teachings, why? Because Jesus is the Living Word of God (John 1:1) What they are hearing is not mans interpretation but directly from God

Second notice the demon addressed Jesus as the Holy One of God, this is a Messianic title, (Psalm 16:10) the demon was actually affirming that Jesus is the Christ, the Son of God, and he affirmed Jesus power and authority by saying “Have you come to destroy us”? The demon knew Jesus is the King of Kings, the Lord of Lords, the Christ, the Son of God!

And Jesus rebuked him, saying, Hold thy peace, and come out of him. And when the unclean spirit had torn him, and cried with a loud voice, he came out of him.  And they were all amazed, insomuch that they questioned among themselves, saying, What thing is this? what new doctrine is this? for with authority commandeth he even the unclean spirits, and they do obey him. Mark 1:25-27

Jesus rebuked the demon and commanded it to come out of the man, everyone was astonished, why? Because up until this point nobody has exercised a demon before, think about all the prophets of the Old Testament, nobody has ever had power and authority over demons except Jesus, why? Because he is the Lord of Lords, the Christ , the Son of God

I believe this is also a demonstration of the New Covenant, a Better and more powerful covenant , an eternal covenant with better promises! What new doctrine is this? The people asked, its the New Covenant, its the Word became Flesh and living among us (John 1:14)

And immediately his fame spread abroad throughout all the region round about Galilee. Mark 1:28

The gospel of Jesus Christ spread like wild fire, why? Because Christ demonstrated his power over sin, death, and hell. The New Covenant has come, and Jesus has come to set the captives Free Amen!