The Mistake of the Pharisees
The fatal mistake of the Pharisees was that they were doing righteousness for the wrong reasons. They were doing righteous acts to be seen of men and not to glorify God (Matt. 5:16). Jesus was constantly reminding them of what they were doing wrong but they were living so much to the flesh, they could not hear the words of the Spirit (Matt. 9:13; 12:7; Prov. 21:3).
Jesus was telling the Pharisees how to clean the inside of the cup by being true servants to others so they would not be hypocrites (Matt. 23:11, 25). He was telling them how to enter the kingdom of heaven within (Matt. 23:13; Luke 17:21). This is the key to knowledge of how to be truly converted from the inside.
In the example of the good Samaritan, Christ was showing the Pharisees that the people they called religious fakes were more compassionate to the needy than they were (Luke 10:30-37). Those who handled the Law of Moses were holding people back, keeping from them the keys to the kingdom (Luke 11:52). The understanding of how to enter the kingdom was then given to Peter (Matt. 16:19). Peter knew what the Pharisees were doing wrong. Many Pharisees did repent and become obedient to the faith (Acts 6:7).
Unrepentant sinners do bad works. Repentant sinners do good works for God - works meant for repentance (Acts 26:20). Performing good works for God by imitating Jesus Christ’s works is how you overcome the deeds of the flesh (Rev. 2:26). You live to the Spirit (Rom. 8:13-14). Then you do not carry out the desires of the flesh (Gal. 5:16).
Once you put your hand to the plow, which represents doing good works for God, do not look back or get weary of well-doing (Gal. 6:9; 2 Thess. 3:13). Soon you will be a new creation with Christ formed in you (Gal. 6:15; 4:19). Then you will be complete (2 Cor. 13:9, 11). You will also be a peculiar person, zealous for good works and not worthless, but worth more (Titus 2:14; 1:16).
This is the knowledge of the truth which is according to godliness and it requires discipline (Titus 1:1; 1 Tim. 4:7). If anyone advocates a different doctrine than this, he is conceited and understands nothing (1 Tim. 6:3-4).
Be a sheep and not a goat (Matt. 25:33-46). Allow God to crush Satan (your old nature) under your heel (Rom. 16:20). Soon, as a happy slave of Christ, you will be doing the Will of God from your heart and will escape from the snare of the devil which traps others to do his will (Eph. 6:6; 2 Tim. 2:26). You will not be caught making the same mistake the Pharisees of old made.