Oh, sir, in the course of these years, what awful proofs I have had, and have given, of the deceitfulness and vileness of my heart. What wretched returns of my ingratitude and perverseness I have made for mercies received, is known only to him who has borne with me. Much of this dark part of my story I have forgotten, but I remember enough to fill me with shame. It is true that, as to my outward profession, I have been preserved from making any considerable blots, but this enhances the wonder and the mercy; for I am conscious to myself of hair-breadth escapes from such entanglements as might and would, without the Lord’s interposition, have issued in final apostasy. And in this space of time, how many whom I had reason to esteem better than myself have I seen fall (some I fear to rise no more), while I am still left to speak of his mercy. I have seen enough to remind me of the difference of setting out , and holding out to the end, and to warn me that we can have no security from gifts, labours, services, or sufferings, from clear views, or past experiences; but that from first to last our only safety is in the power, compassion, and faithfulness of our great Redeemer.
– Letters of Newton, pp. 412-13.