“When I do good I feel good and when I do bad I feel bad, and that’s my religion”

A quote about Abraham Lincoln’s religion was recorded by William Henry Herndon (1818-1891), Lincoln’s 20-year friend, law partner and biographer, in the book Herndon’s Lincoln: The True Story of a Great Life, Volume III (1890) by William H. Herndon and Jesse William Weik:
   
“Inasmuch as he was so often a candidate for public office Mr. Lincoln said as little about his religious code as possible, especially if he failed to coincide with the orthodox world. In illustration of his religious code I once heard him say that it was like that of an old man named Glenn, in Indiana, whom he heard speak at a church meeting, and who said: ‘When I do good I feel good, when I do bad I feel bad, and that’s my religion.’”
   
 
Wikiquote: Abraham Lincoln
Abraham Lincoln (12 February 1809 – 15 April 1865) was the 16th President of the United States, serving from March 1861 until his assassination in April 1865.
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Posthumous attributions
. When I do good I feel good, when I do bad I feel bad, and that’s my religion.
Quoted in 3:439 Herndon’s Lincoln (1890), p. 439: Inasmuch as he was so often a candidate for public office Mr. Lincoln said as little about his religious code as possible, especially if he failed to coincide with the orthodox world. In illustration of his religious code I once heard him say that it was like that of an old man named Glenn, in Indiana, whom he heard speak at a church meeting, and who said: “When I do good I feel good, when I do bad I feel bad, and that’s my religion.”
 
Wikipedia: William Herndon (lawyer)
William Henry Herndon (December 25, 1818 – March 18, 1891) was a law partner and biographer of President Abraham Lincoln. He was an early member of the new Republican Party and was elected mayor of Springfield, Illinois.
 
Newspapers.com
11 October 1889, Lucifer, The Light Bearer (Valley Falls, KS), pg. 1, col. 3:
The Religious Views of Abraham Lincoln.
From Freethought, San Francisco
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William H. Herndon, for twenty years a friend and law partner of Abraham Lincoln, has written a life of that great figure of American History, the sixteenth president of the United States.
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He (Herndon—ed.) says:
 
“Inasmuch as he was so often a candidate for public office Mr. Lincoln said as little about his religious opinions as possible, especially if he failed to coincide with the orthodox world. In illustration of his religious code, I once heard him say that it was like that of an old man named Glenn, in Indiana, whom he heard speak at a church-meeting, and who said: ‘When I do good I feel good and when I do bad I feel bad, and that’s my religion.’”
   
Google Books
Herndon’s Lincoln:
The True Story of a Great Life
Volume III
By William H. Herndon and Jesse William Weik
Chicago, IL: Belford-Clarke Co.
1890
Pg. 439:
Inasmuch as he was so often a candidate for public office Mr. Lincoln said as little about his religious opinions as possible, especially if he failed to coincide with the orthodox world. In illustration of his religious code I once heard him say that it was like that of an old man named Glenn, in Indiana, whom he heard speak at a church meeting, and who said: “When I do good I feel good, when I do bad I feel bad, and that’s my religion.”
   
Sue Brewton’s Blog
No, that is not what Abraham Lincoln said.
JANUARY 31, 2016 / SUE BREWTON
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The Correct Quote
✓“When I do good I feel good, when I do bad I feel bad, and that’s my religion.”
Unknown
Herndon’s Lincoln: The True Story of a Great Life, volume III, chapter XIV
William H. Herndon and Jesse William Weik
 
According to Herndon (Lincoln’s friend and law partner), Lincoln attributes this quote to an old man named Glenn in Indiana.  Since there have been multitudes of people named Glenn in Indiana and no other identifying information is provided, we can only attribute this quote to unknown.  Of course, it could be attributed to “old man Glenn in Indiana,” but this ultimately leads to “unknown.”  Here is the quote found in Herndon’s Lincoln: The True Story of a Great Life, volume III, chapter XIV first published in 1889.
 
Reddit—Quotes
Posted by u/sylsau December 23, 2021
“When I do good, I feel good. When I do bad, I feel bad. That’s my religion.” ― Abraham Lincoln