David Burns, one of the founders of CBT, refers to the belief that one’s worth is entirely based upon his achievements as “Achievement Addiction”, and notes that there are many disadvantages to this way of thinking. He suggests having a different formula for determining one’s self-worth (e.g., intrinsic self-worth, totally irrespective of one’s achievements) or of disposing of the idea of self-worth altogether. My question: is there any evidence in favor or against this philosophy (that one’s worth is based entirely upon his achievements) in the Torah or in logic? And what about one partially basing his self-worth on his achievements? Please provide sources if possible.
It would appear that Judaism believes it is possible for a person to be not-OK (a rasha) and it is also possible for a person to be very OK (a tzadik).
However, importantly, that which makes you not-OK is morally perverse behaviour (a rash) and that which makes you very OK is exemplary moral behaviour (a tzadik) - not "accomplishments".
Rabbi Zelig Pliskin in his book Gateway to Happiness deals with this issue at length and brings dozens of sources in Ch. 6. The tl;dr version is that every human being is created in the image of G-d and thus has very great potential. Just by being born one's value is tremendous. One should be proud of one's accomplishments. Prided used to spur one to do good can be meritorious. But one must also not be unrealistically critical and too hard on themselves.
I will add that one person's accomplishments do not automatically make him better than another, because every person is judged against their personal potential, not others. The Beit Elokim by Mabit makes this point at length in his introduction.
Thus a great person can take pride in his accomplishments and still be humble, because he realizes he is just doing his personal best to fulfill his G-d-given potential.
Rabban Yohanan ben Zakkai received [the oral tradition] from Hillel and Shammai. He used to say: if you have learned much Torah, do not claim credit for yourself, because for such a purpose were you created. Ethics of the Fathers 2:8