And a ruler asked him, “Good Teacher, what must I do to inherit eternal life?” 19 And Jesus said to him, “Why do you call me good? No one is good except God alone. 20 You know the commandments: ‘Do not commit adultery, Do not murder, Do not steal, Do not bear false witness, Honor your father and mother.’” 21 And he said, “All these I have kept from my youth.” 22 When Jesus heard this, he said to him, “One thing you still lack. Sell all that you have and distribute to the poor, and you will have treasure in heaven; and come, follow me.”23 But when he heard these things, he became very sad, for he was extremely rich. - Luke 18:18-23
The rich young ruler thought that he was well accomplished. That he had done the commandments well. That he was, for lack of a better word, good.
Contrast this with Christ Jesus. When He is called good, He asks, "Why do you call Me good? No one is good except God alone." Even Christ Jesus, who is equal with the Father, does not grasp or cling to this -- and He brushes off His own works. Why call Me good -- you aren't confessing that I am God, so don't say that.
If Christ Jesus, My Lord and Savior, is thus so hesitant to call even Himself "good", how could I dare to ever look at my own works and say, "I am progressing... I am more good today than I was yesterday!"
Vanity of Vanities, all is Vanity!