When I was in seminary a professor challenged the account of the woman taken in adultery by saying that the Pharisees would not have hesitated to pick up the first stone. Because of their adherence to the law, he said, they considered themselves to be good enough and they certainly would have been bold enough to stone the woman. But, when Jesus said for the one who is without sin to cast the first stone, they all walked away. The professor believed that indicated that the passage was a later addition to the true text.
I do not believe that I have ever met a legalist who was not afraid of the truth about themselves. In fact, I think it is why the passages that tell them to "fear God" resonate so strongly with them. The law is not only a schoolmaster; it is a harsh master, one who knows the whole truth. The law exposes sin, no matter how deeply we try to hide it. No one else may know the thoughts of a man’s mind, but - under the law - such things are known.
I have known brazen legalists, quick to accuse others and pronounce judgment. I have known insidious legalists who connive to reveal the secrets of others. I have known cruel legalists who would take pleasure in stoning others. But I have never known one who had no internal fear of God and the truth.
Most of the legalist’s boldness is not from inner strength, but from inner fear. It is an attempt to distract, to project, to point the finger at others so that the finger doesn’t point at them. But in secret they fear the exposure they bring on others. They are afraid that their lies will be revealed, that their children will somehow fall short and uncover family weaknesses, or that they will slip and others will know the truth. So they are quick to lie again, quick to reject even the ones closest to them, and quick to blame others and situations.
We all sin, but those who live under the law and refuse to see the grace and love of Jesus live in fear of judgment. They not only see sin in more places than we do, they have little hope when they do sin.
The Pharisees walked away that day because, under the conviction of the Holy Spirit through the words of Jesus, they could not risk the truth being revealed. The passage says that they walked away "one by one." As each one realized what he would have to risk by throwing that first stone, he decided it wasn’t worth it.
Some may see things differently, of course, but it seems to me that much of the negative behavior we see and experience from legalists comes out of fear. Even their supposed pride is a desire to be bold in the face of their fears.
The law causes fear.
The good news is that we are no longer under law, those who belong to Jesus, but under grace.