And when Jesus finished these sayings, the crowds were astonished at his teaching, for he was teaching them as one who had authority, and not as their scribes.
The crowds didn't hear the sermon on the mount and remain indifferent. They didn't just think it was a nice bit of moral teaching. They were astonished. It blew their minds. They couldn't believe what he was saying. If we look at Jesus' teaching and don't think he is either God or a lunatic, then we haven't understood it. Here is a man that has claimed that it's humble and broken people who are blessed, not the proud "successful" people. He has raised the bar on the level of righteousness that the Pharisees demanded. He said that you need to be perfect, you need to love your enemies and turn the other cheek. He has called the respected religious leaders hypocrites. He said that there are people claiming to follow God who are actually on a path to destruction. It's not only shocking to the people at the time but also for us - it's the opposite of the common opinions held in modern society.
It is crazy. Or true