“If you deliver an opinion at all, it is mere stupidity not to do it with an air of conviction and well-founded knowledge. You make it your own in uttering it, and naturally get fond of it.”

Source: The Vastalimi Gambit (2013), Chapter 11

The Way to Divine Knowledge (1762).
Context: If Reason seems to have any Power against Religion, it is only where Religion is become a dead Form, has lost its true State, and is dwindled into Opinion; and when this is the Case, that Religion stands only as a well-grounded Opinion, then indeed it is always liable to be shaken; either by having its own Credibility lessened, or that of a contrary Opinion increased. But when Religion is that which it should be, not a Notion or Opinion, but a real Life growing up in God, then Reason has just as much power to stop its Course, as the barking Dog to stop the Course of the Moon. For true and genuine Religion is Nature, is Life, and the Working of Life; and therefore, wherever it is, Reason has no more Power over it, than over the Roots that grow secretly in the Earth, or the Life that is working in the highest Heavens. If therefore you are afraid of Reason hurting your Religion, it is a Sign, that your Religion is not yet as it should be, is not a self-evident Growth of Nature and Life within you, but has much of mere Opinion in it.

Pastwatch: The Redemption of Christopher Columbus (1996)

"Mount Shasta" in Picturesque California (1888-1890) page 165; reprinted in Steep Trails (1918), chapter 5
1880s

Part 5: "The World of One Physicist", "The 7 Percent Solution", p. 255
Surely You're Joking, Mr. Feynman! (1985)

Milton's God (1961; repr. London: Chatto & Windus, 1965) p. 261.
Other

Source: The Darkest Kiss

I am strong enough to bounce back, says Rohit Sharma, NDTV Sports, 4 December 2012 https://sports.ndtv.com/cricket/i-am-strong-enough-to-bounce-back-says-rohit-sharma-1544263,