They were amazed at His teaching; for He was teaching them as one having authority, and not as the scribes. Mark 1:22
There’s a common understanding that one has to earn the right to speak. Who wants to listen to—much less follow—a man whose words lack authority, who’s not credible?
Here Jesus compels busy men with a word to follow him, and they do. He commands a demon to leave a man and he does. He reads scripture and he speaks as if he wrote it, and he essentially did.
The disciples cast their lots with him and no longer their nets on his command. They didn’t even know who he was. The unclean spirit knew exactly who he was and wanted nothing to do with “the Holy One of God.”
What’s Mark trying to tell us? In his inimitable fashion, waste no time responding to the Lord’s request. “Repent and believe in the gospel!” Tomorrow may not come.