Gratitude — as conviction, practice, and discipline — is an essential nutrient, a kind of spiritual amino acid for human growth, joy, and creativity. Take away the daily experience and expression of gratitude, and life is quickly diminished. Like a weakened immune system, the spirit is left vulnerable to the diseases of cyncism, anger, low-grade depression, or at least an edgy sense of dissatisfaction. Gratitude-deprived, we suffer a relentless loss of vitality and delight.
— Alan Jones, Seasons of Grace by Alan Jones, John O'Neil