“Courage and perseverance have a magical talisman, before which difficulties disappear and obstacles vanish into air.”
In recent years this has often been misquoted as: "Patience and perseverance have a magical effect before which difficulties disappear and obstacles vanish".
Oration at Plymouth (1802)
Context: Courage and perseverance have a magical talisman, before which difficulties disappear and obstacles vanish into air. These qualities have ever been displayed in their mightiest perfection, as attendants in the retinue of strong passions.
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John Quincy Adams 52
American politician, 6th president of the United States (in… 1767–1848Related quotes

“Great difficulties may be surmounted by patience and perseverance.”
Letter to John Adams (27 November 1775)
Source: The Quotable Abigail Adams
Context: I feel anxious for the fate of our monarchy, or democracy, or whatever is to take place. I soon get lost in a labyrinth of perplexities; but, whatever occurs, may justice and righteousness be the stability of our times, and order arise out of confusion. Great difficulties may be surmounted by patience and perseverance.

"All Pervading Consciousness"
Context: Yet what are seas and what is air? For all
Is God, and but a talisman are heaven and earth
To veil Divinity. For heaven and earth,
Did He not permeate them, were but names;
Know then, that both this visible world and that
Which unseen is, alike are God Himself,
Naught is, save God: and all that is, is God.

As quoted in Mohammad Ali Jinnah : A Political Study (1962) by M. H. Saiyid, p. 9

As quoted in Teen Ink : What Matters (2003) by Stephanie H. Meyer, John Meyer, and Peggy Veljkovic, p. 309

Still Me (1999); also quoted at the Christopher Reeve Foundation http://www.christopherreeve.org/site/c.geIMLPOpGjF/b.1097025/k.6FF5/Christopher_and_Dana_Reeve.htm
Context: When the first Superman movie came out, I gave dozens of interviews to promote it. The most frequent question was: What is a hero? My answer was that a hero is someone who commits a courageous action without considering the consequences. Now my definition is completely different. I think a hero is an ordinary individual who finds the strength to persevere and endure in spite of overwhelming obstacles. They are the real heroes, and so are the families and friends who have stood by them.

[Beecham admitted to Neville Cardus that he had made this up on the spur of the moment to satisfy an importunate journalist; he acknowledged that it was an oversimplification. (Neville Cardus: 'Sir Thomas Beecham, A Memoir', 1961)]