Indeed, this is so important to remember when trying to evaluate the religious ideas of the Framers, and the form they took in the drafting of the Constitution.
There's an interesting tension in the thought of both TJ and Adams WRT God and religion. On the one hand, God is the source of individual liberty; on the other, religion can be a grave threat to individual liberty (e.g., the Roman Church in their view). Not to mention that, historically, religion has often enough been the pretext for going to war; on the other hand, the best defense against tyranny is to vest the sovereignty of the state in The People (as the Framers did). But this only works on the understanding that The People are a people "under God."
In short, for TJ and Adams both, true human liberty is achieved only "under God"; where God is absent, the tyrant will fill His place.
YHAOS, thank you again for the link to the TJ archive. I breezed through it just to see what-all was there. Truly, it is the "mother lode" of TJ's writings over a lifetime. A wonderful resource!
Yes, and this tension is no better reflected than in the following outburst of Adams in a letter to TJ:
Twenty times in the course of my late reading have I been on the point of breaking out, "This would be the best of all possible worlds, if, there were no religion in it!!!'' But in this exclamation I should have been as fanatical as Bryant or Cleverly. Without religion this world would be something not fit to be mentioned in polite society, I mean hell.
. . . . . John Adams, letter to Thomas Jefferson, Quincy, April 19, 1817, The Writings of Thomas Jefferson, Albert Ellery Bergh, Editor, ME, vol. 15, pg 105.
Of interest, we might also note that this fragment of a paragraph in a much larger letter is a favorite target of Atheists to quote out of context where they cite only the first sentence, leaving out the meat of Adams thought which is expressed in the balance of the quote.
. . . thank you again for the link to the TJ archive
My honor, Dear Lady, and always a pleasure to carry on a conversation with you.