"Expect great things; attempt great things."
At a meeting of Baptist leaders in the late 1700s, a newly ordained minister stood to argue for the value of overseas missions. He was abruptly interrupted by an older minister who said, "Young man, sit down! You are an enthusiast. When God pleases to convert the heathen, he'll do it without consulting you or me."
That such an attitude is inconceivable today is largely due to the subsequent efforts of that young man, William Carey.