And he who receiveth all things with thankfulness shall be made glorious; and the things of this earth shall be added unto him, even an hundred fold, yea, more. Doctrine and Covenants 78:19
"It seems as though there is a tug-of-war between opposing character traits that leaves no voids in our souls," said President James E. Faust, then a member of the Quorum of the Twelve, during the April 1990 general conference. "As gratitude is absent or disappears, rebellion often enters and fills the vacuum. I do not speak of rebellion against civil oppression. I refer to rebellion against moral cleanliness, beauty, decency, honesty, reverence, and respect for parental authority.
"A grateful heart is a beginning of greatness. It is an expression of humility. It is a foundation for the development of such virtues as prayer, faith, courage, contentment, happiness, love and well-being."