--- Augustine of Hippo, Epistolae 145, 4; quoted in Peter Brown, Augustine of Hippo (1967, 2000) p. 375
Context in Brown: "It is Pelagius, not Augustine, who harps on the terrors of the Last Judgment: to which Augustine simply remarked that ‘a man who is afraid of sinning because of Hell-fire, is afraid, not of sinning, but of burning.’"