As to the study of theology. How far it may be expedient to adopt some system or body of divinity as a text or ground whereon to proceed, I am not quite determined; and which of these learned summaries is the best, I shall not attempt to decide until I have read them all. . . . Calvin, Turretin, Witsius, and Ridgely, are those with which I have formerly been most acquainted. But indeed, of these, at present, I can remember little more than that I have read them, or the greatest part of them. I recollect just enough to say, that, though I approve and admire them all, I have at the same time my particular objections to them all, as to this use of them. The Bible is my body of divinity; and, were I a tutor myself, I believe I should prefer the Epistles of St. Paul, as a summary, to any human systems I have seen, especially his Epistles to the Romans, Galatians, the Hebrews, and Timothy. . . . I would have my pupils draw their knowledge as immediately from the fountain-head as possible. I care not how extensive and various their reading of good authors may be under their tutor’s eye; the more so the better. He will improve the differences they will find among learned and spiritual men, into an argument to engage them to study the Scripture more closely, and to bring every debated sentiment to be tried, and finally determined, by that unerring standard.
John Newton, A Plan of Academical Preparation in The Complete Works of John Newton, 3:507-08.