We’re often taught to be careful of the difference between joy and happiness. Happiness, it is said, is an emotion that depends upon what “happens.” Joy by contrast, is supposed to be enduring, stemming deep from within our soul and which is not affected by the circumstances surrounding us. . . . I don’t think God had any such hair-splitting in mind. Scripture uses the terms interchangeably along with words like delight, gladness, blessed. There is no scale of relative spiritual values applied to any of these.[
Joni Eareckson Tada