III. Ministers are fishers by office; they are catchers of the souls of men, sent “to open the eyes of the blind, and to turn them from darkness to light, and from the power of Satan unto God,” Acts 26:18. Preachers of the gospel are fishers; and their work, and that of fishers, agree in several things.
1. The design and work of fishers is to catch fish. This is the work that preachers of the gospel have taken in hand, even to endeavour to bring souls to Christ. Their design in their work should be the same. Tell me, O my soul, what is thy design in preaching? for what end dost thou lay the net in the water? is it to shew thy gifts, and to gain the applause of men? Oh! no. Lord, thou knowest my gifts are very small; and had I not some other thing than them to lean to, I had never gone to a pulpit. I confess, that, for as small as they are, the devil and my corruptions do sometimes present them to me in a magnifying glass, and so would blow me up with wind. But, Lord, thou knowest it is my work to repel these motions. An instance of this see in my Diary, Jan. 1. 1699. But of this see afterwards.
2. Their work is hard work; they are exposed to much cold in the water. So is the minister’s work.
3. A storm that will affright others, they will venture on, that they may not lose their fish. So should preachers of the gospel do.
4. Fishers catch fish with a net. So preachers have a net to catch souls with. This is the everlasting gospel, the word of peace and reconciliation, wherewith sinners are caught. It is compared to a net wherewith fishers catch fish….

—Thomas Boston, The Whole Works of Thomas Boston: A Soliloquy on the Art of Man-Fishing, ed. Samuel M‘Millan, vol. 5 (Aberdeen: George and Robert King, 1849), 10–11.