Well I did, but it was statements I was referring to, not a single letter. There are far more founding members of the Constitution whom believe the same. Moreover, in that letter that you posted, it implies the backwards thinking of Christians rather than the progression of science for modern thought. That thought reigns today by most Christians, and the easiest example is Creationism Vs. Evolution.
You need to read and understand what was implied by the context of the letter you quoted.
I've read most of Jefferson's writings, as well as most of the founding fathers. I understand quite well.
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