Within man is a need to pay back in kind the good done for him. Therefore, the Chovos HaLevovos explains that a driving force in our service to HASHEM should be an overwhelming urge to somehow repay HASHEM for all the kindness that He has bestowed upon us.
This, however, brings a question. We are the recipients of so much good. We have hands and fingers, and arms and legs. We have our mobility and our health. We gaze upon fantastic sights: flowers and trees, meadows and lakes, majestic mountain peaks and lush valleys. We enjoy a vast array of foods, each with its own taste, flavor and aroma. In short, we have tremendous good. Why aren’t we overwhelmed with a need to serve HASHEM, at least as some minor way of paying back all of the good that He has done for us?