Mechanically keeping the law is only the beginning of righteousness. By emphasizing principle, Christ came to magnify, not to destroy God's law.
Religious bumper stickers fall short of revealing the full counsel of God, which is more complex than 'believe on the Lord Jesus and you shall be saved.'
The people of Lystra and Derbe mistake Paul for Hermes and Barnabas for Zeus. When Paul convinces the crowds that he and Barnabas are not gods, they are rejected.
The keeping of the law is a practical response to God, providing us with principles for our lives, establishing our character and implanting God's values.
Self-righteous people tend to trust in their own heart, be wise in their own eyes, justify themselves, despise or disregard others, and judge or condemn others.