‘They read the Word without seeing Jesus in it and they become zealous for the law. They end up unknowingly seeking to make themselves righteous by the law. Legalism is very subtle and insidious.

Many legalists are unaware that they are trapped in legalism. They would never admit they are legalists and may even preach strongly against legalism.

There are also people who attack the gospel of grace because they are blinded by their zeal for the law and how man needs to make himself better
through right doing. I truly believe that many of them are genuine and sincere; nevertheless, they are sincerely wrong.’

Joseph Prince in
The Power of Right Believing.

Sadly, people can preach about being sons instead of slaves, yet plod along in the law that makes slaves out of sons. People can be legalists because of their doctrine or because that is the tendency of the fleshly heart. There is a radical difference between the old and the new covenant. In the old it was obey and live. But in the new it is live and obey. That is allow Christ to be your life, live in Him and allow Him to express His life through you.

If, so to speak you have your foot in a legalistic performance activity, you place yourself in the old covenant. Here you are back in the Ten Commandments and smothered in the law of sin and death. You have allowed yourself to be captured in the knowledge of good and evil and its stink of death. You stumble about under the authority of Satan and the curse. Who needs that? No one. You have been transported from darkness to light. Live in the arms of the Father where He has placed you! You belong to the realm of resurrection and light – Jesus.