Said the Intellect - The first foundation upon which the entire construct stands is, that the Heavenly Will wanted that man should complete himself and all that was created for him, and this itself shall be his merit and reward. His merit - because it will be found that he occupies himself and will achieve this completeness, and when he he reaches it - he will gain benefit only from the achievement of his hands and his portion from all of his effort. His reward - for in the end he will be that which is completed, and will enjoy goodness forever and ever:
We Are Meant to Complete Ourselves and All Creation
Da'at Tevunot 14:1