A diary entry by the Rev. Donald Macfarlane, taken from The Memoir and Remains of Rev. Donald Macfarlane. See note at the top of page 355.
I found out after the meeting tonight that I was led to speak a word in season to some in the meeting. I was prepared beforehand in a mysterious manner to speak as I did. For the last few days Satan was harassing me terribly with some of my old sins which I had good reason to believe the Lord had forgiven me long ago. But the evil one was coming day and night with a burden of these on his black back to take away my hope. This crushed my spirit, but I was fleeing to the blood of Jesus, and the evil one had to flee away, for he cannot stand the argument of the blood by which his head was bruised.
I was put in a condition to speak from the heart to other hearts. If we would speak to poor sinners for their benefit we ourselves must be great sinners in our experience. I felt greatly relieved myself when speaking, and some others got relief too! Ministers are instruments in the hand of God, and He uses them according to His own good will. He permits Satan to harass them with temptations in order to prepare them, as with a sharpening stone, for His work.
If the tempter knew that, he was, by his temptations, preparing Gods servants to destroy his own kingdom he would not be so busy tormenting them. Some have called Satan, “The great fool”. If you saw a man trying to break in pieces a large rock by striking his head against it, you would say to that man, “You are a big fool: you are only hurting yourself.” So it is with Satan: in everything he does to destroy the kingdom of Christ, he only works for the destruction of his own kingdom. His agents are as foolish as himself. They are exceedingly laborious in their devices and efforts to overthrow the kingdom of Christ, and are, in all they do, working out their own everlasting ruin.