Not a few others could be named, but I must reserve a paragraph for special mention of three: Martin Luther, John Calvin, and Karl Barth. Barth's commentary . . . I read as an undergraduate. If in those days, and since, I remained and have continued to be a Christian, I owe the fact in large measure to that book, and to those in Cambridge who introduced it to me. Calvin has long been a companion whose patient exegesis is a model of critical and theological thoroughness. In the summer of 1953, in the University Library of Göttingen, I read through Luther's Scholia on Romans . . . with a sustained enthusiasm and even excitement which I never thought 400 large pages of medieval Latin could evoke. Less sound in detail than Calvin, Luther wrestles at perhaps even greater depth with sin and righteousness, race and predestination, and rarely fails to reach the heart of the matter, and to take his reader with him. To have sat at the feet of these three interpreters of Paul is one of the greatest of privileges." - C.K. Barrett, A Commentary on the Epistle to the Romans (London: Adam & Charles Black, 1957), vi.For those who wondered how his views changed over the next 40 years, Barrett adds this in the 2nd 1991 edition:
"There is nothing in the preface to the first edition of this Commentary that I wish to retract. My gratitude to the writers and teachers mentioned there is undiminished, but it is expanded now to include many more whose work on Romans and Pauline theology has greatly enhanced my own understanding." - C.K. Barrett, A Commentary on the Epistle to the Romans (Hendrickson, 1991), ix.