“In the mean time he will enable you to sow the seed in patience, leaving the event in his hands. Though it does not spring up visibly at once, it will not be lost. I think He would not have sent you if He had not a people there to call; but they can only come forth to view as He is pleased to bring them. Satan will try to hinder and disturb you; but he is in a chain which he cannot break, nor go a step farther than he is permitted. And if you have been instrumental to the conversion of but a few, in those few you have an ample reward already for all the difficulties you have or can meet with. It is more honourable and important to be an instrument of saving one soul, than to rescue a whole kingdom from temporal ruin. Let us therefore, while we earnestly desire to be more useful, not forget to be thankful for what the Lord has been pleased already to do for us; and let us expect, knowing whose servants we are, and what a Gospel we preach, to see some new miracles wrought from day to day: for indeed every real conversion may be accounted miraculous, being no less than an immediate exertion of that power which made the heavens, and commanded the light to shine out of darkness. Your little telescope is safe. I wish I had more of that clear air and sunshine you speak of, that with you I might have more distinct views of the land of promise. I cannot say my prospect is greatly clouded by doubts of my reaching it at last; but then there is such a languor and deadness hangs upon my mind, that it is almost amazing to me how I can entertain any hopes at all. It seems, if doubting could ever be reasonable, there is no one who has greater reason for doubting than myself. But I know not how to doubt, when I consider the faithfulness, grace, and compassion of Him who has promised. If it could be proved that Christ had not died, or that he did not speak the words which are ascribed to him in the Gospel, or that he is not able to make them good, or that his word cannot safely be taken; in any of these cases I should doubt to purpose, and lie down in despair.”
-John Newton, The Works of John Newton: Volume 1 (pages 698-699)