John Newton
Writing to his disciple Richard Johnson who was the chaplain of the first fleet, and the first gospel preacher in Australia. Johnson was getting discouraged by the lack of fruit thus far, and Newton wrote to encourage him with these words. 

“I have not been disheartened by your apparent want of success. I have been told that skillful gardeners will undertake to sow and raise a salad for dinner in the short time while the meat is roasting. But no gardener can raise oaks with such expedition. You are sent, not to sow salad seeds, but to plant acorns; and your labor will not be lost, though the first appearance be very small and the progress very slow. You are, I trust, planting for the next century. I have a good hope that your oaks will one day spring up and flourish, and produce other acorns, which in due time, will take root, and spread across the island nations in the Southern Ocean.”