"My heart is sunk…. It seemed to me I should never have any success among the Indians. My soul was weary of my life; I longed for death, beyond measure."

So wrote David Brainerd, describing his early weeks as a missionary to Native Americans at the beginning of the 1700s. Things didn't improve much for the first two years, in fact. He felt his prospects of winning converts "as dark as midnight."

Three years into the work, though, he finally witnessed a revival among the Indians of Crossweesung in New England, and after another year and a half, the number of converts numbered 150—not much by today's mass evangelistic standards, but profoundly significant in his day. Unfortunately, Brainerd died after only five years on the mission field, at age 29.

After Brainerd's death, Jonathan Edwards—whom some consider America's greatest theologian—published Brainerd's journals. These were read widely in America and Europe. In fact, William Carey, the "father of modern missions," the man who ignited the modern Protestant missionary movement, which has been responsible for millions upon millions of conversions worldwide, pointed to Brainerd's journals as a key source of his inspiration to take up the missionary life.

Who, then, can judge whether our work is worthwhile? Certainly we cannot when we're in the midst of discouragement.