And when Jesus heard it, he said to them, “Those who are well have no need of a physician, but those who are sick. I came not to call the righteous, but sinners.”
Mark 2:17

Two meanings:
1) Those who already understand righteousness and are living it, don't need to be instructed.
2) Those who believe they are righteous despite their disobedience are unable to hear instruction in righteousness.