“They would fail. We would always fail. We weren’t built to do anything but fail. We had the wrong kind of motives and we couldn’t change them. We had a built-in short-sightedness and an inherent selfishness and a self-concern that made it impossible to step out of the little human rut we traveled.”

Presidency (1977–1981), Farewell Address (1981)
Context: Nuclear weapons are an expression of one side of our human character. But there is another side. The same rocket technology that delivers nuclear warheads has also taken us peacefully into space. From that perspective, we see our Earth as it really is — a small and fragile and beautiful blue globe, the only home we have. We see no barriers of race or religion or country. We see the essential unity of our species and our planet; and with faith and common sense, that bright vision will ultimately prevail.
Another major challenge, therefore, is to protect the quality of this world within which we live. The shadows that fail across the future are cast not only by the kinds of weapons we have built, but by the kind of world we will either nourish or neglect.

Attributed to R.D. Lang in: Jack Lee Seymour, Margaret Ann Crain, Joseph V. Crockett (1993) Educating Christians. p. 53

Vol. I, Letter 7
Letters That Have Helped Me (1891)

Fail to prepare; prepare to fail.
By failing to prepare, you are preparing to fail.
Attributed to Franklin in Julita Agustin-Israel, Lakas ng Loob, 1996, p. 53 https://books.google.com/books?id=2Z59AAAAMAAJ&q=prepare; there is no evidence that he coined any forms of this quote.
Misattributed

Source: How Proust Can Change Your Life

(A.J. Broomhall. Hudson Taylor and China’s Open Century, Book Five: Refiner’s Fire. London: Hodder and Stoughton and Overseas Missionary Fellowship, 1985, 175).

Source: The Tenant of Wildfell Hall (1848), Ch. XXX : Domestic Scenes; Helen to Arthur