"A joyful and pleasant thing it is to be thankful."
- Book of Common Prayer (1892)
"Gratitude is not only the greatest of virtues, but the parent of all the others."
- Cicero, Pro Plancio (54 BC)
"Your Lord is bountiful to mankind: yet most of them do not give thanks."
- Muhammad, Koran, 27.73
"We often take for granted the very things that most deserve our gratitude."
- Cynthia Ozick (b. 1928)
"One looks back with appreciation to the brilliant teachers, but with gratitude to those who touched our human feeling."
- Carl Gustav Jung (1875-1961)
"The best way to show my gratitude to God is to accept everything, even my problems, with joy."
- Mother Teresa (1910-1997)
"At times our own light goes out and is rekindled by a spark from another person. Each of us has cause to think with deep gratitude of those who have lighted the flame within us."
- Albert Schweitzer (1875-1965)
"Let us come before his presence with thanksgiving, and make a joyful noise unto him with psalms."
- The Bible, Psalms, 95:2.
Sources: Wikipedia, Wikiquote, Bartlett's Quotations, King James Bible, WisdomPortal, Book of Common Prayer.