The Thankful Principle follows Marcia Day Brown's life-changing journey into thankfulness. While frustrated and dealing with a troubled teenage daughter, the author reluctantly began thanking God in the midst of trying circumstances, according to Philippians 4:6-7. Feeling empowered, she began applying it to other areas of her life. Dramatic results followed. Through sharing her testimony with friends, strangers, on the mission field of South Africa, and even in a women's prison, the Thankful Principle is continuing to change lives today.