“I do not find in Christianity one redeeming feature” (Jefferson?)

In October 2011, a California atheist group put up a billboard with the following anti-Christian saying attributed to founding father Thomas Jefferson:
 
“I do not find in Christianity one redeeming feature. It is founded on fables and mythology.”
 
Thomas Jefferson’s Monticello library collection found the quotation to be spurious, never said by Thomas Jefferson. The quotation has been falsely attributed to Thomas Jefferson since at least 1906.
 
   
Thomas Jefferson’s Monticello
Spurious Quotes
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“I have recently been examining all the known superstitions of the world, and do not find in our particular superstition [Christianity] one redeeming feature. They are all alike founded on fables and mythology.”
 
We are asked about this one on a fairly regular basis. As with many spurious Jefferson quotes, it is frequently seen on various Internet sites. Many sites do not cite a source, but a good number of those that do attribute this quote to a letter from TJ to a “Dr. Wood.” As far as we know, TJ never wrote to an individual calling him/herself Dr. Wood. Another suspicious element is the statement that he does not find in Christianity “one redeeming feature.” One presumes that Jefferson did, in fact, find some redeeming features in Christianity, otherwise he would not have taken the time to paste together his own versions of the Bible. See the report Jefferson’s Religious Beliefs for more information.
 
Thomas Jefferson’s Monticello
Superstition of Christianity (Quotation)
Quotation: “I have examined all the known superstitions of the world, and I do not find in our particular superstition of Christianity one redeeming feature. They are all alike founded on fables and mythology.”
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Status: We have not found this quotation in any of Jefferson’s known writings
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Comments: Some sources cite this quotation as being from a letter from Jefferson to a “Dr. Woods;” others claim it was to William Short, and still others do not cite a specific document.
 
Google Books
Views of Religion
By Rufus King Noyes
Boston, MA: L.K. Washburn
1906
Pg. 259:
THOMAS JEFFERSON, PRES. U.S.A.
I have recently been examining all the known superstitions of the world, and I do not find in our particular superstition, Christianity, one redeeming feature.They are all alike founded upon fables and mythologies.
 
Google Books
Thomas Paine, the apostle of liberty; an address delivered in Chicago, January 29, 1916. Including the testimony of five hundred witnesses
By John E. Remsburg
New York, NY: The Truth Seeker Co.
1917
Pg. 96:
In a letter to Dr. Woods, Jefferson says: “I have recently been examining all the known superstitions of the world, and do not find in our particular superstition [Christianity] one redeeming feature. They are all alike, founded upon fables and mythologies.”
     
Orange County (CA) Register
Published: Oct. 26, 2011 Updated: Oct. 28, 2011 8:37 a.m.
Atheists’ billboard quote isn’t Jefferson’s
By JON CASSIDY / THE ORANGE COUNTY REGISTER
COSTA MESA – A group of atheists called Backyard Skeptics is planning to unveil a billboard at 1545 Newport Blvd., Wednesday afternoon with a quote from Thomas Jefferson bashing Christianity.
 
The quote reads, “I do not find in Christianity one redeeming feature. It is founded on fables and mythology.”
 
There’s one problem: There’s no evidence Jefferson ever said it. The Jefferson Library Collection at Monticello lists it on a page of spurious Jefferson quotes.
Bruce Gleason, whose group paid for this and other recent atheism billboards that have gone up in O.C. in recent months, said Wednesday he wasn’t sure about the origin of the quote.
 
Huffington Post
Atheists’ Billboard Falsely Attributes Quote To Thomas Jefferson
Posted: 10/27/11 12:11 PM ET
A billboard in Costa Mesa, Calif., is getting some attention, but it’s certainly not the kind its sponsors were hoping for.
 
The sign, paid for by atheist group Backyard Skeptics, includes a quote about Christianity attributed to Thomas Jefferson. But further research reveals there’s no solid evidence that Jefferson ever uttered or wrote the words, the Orange County Register first reported.
 
The billboard includes a picture of Jefferson with the quote: “I do not find in Christianity one redeeming feature. It is founded on fables and mythology.”
 
Experts at the Jefferson Library Collection at Monticello are constantly asked about the quote, the Orange County Register reports. Some say the former president wrote the words in a letter to a Dr. Wood, but officials cannot find trace of any correspondence to a person by that name.