I found his description of his personal beliefs to be very humble, and indicative of a man who has thoughtfully considered what he feels is right, and even further, how organized religion imparts beliefs on others, sometimes to their detriment. “That he ought to be worshipped. That the most acceptable Service we render to him is doing good to his children…the System of Morals and his Religion, as he left them to us the best the World ever saw or is likely to see; but I apprehend it has received various corrupting changes”.
I wonder if Franklin had led a less successful life, and experienced more tragedy, if his belief would have been as strong, as he indicates his own prosperity strengthens his belief. Perhaps he can still believe because he has not had to face the cruelty of the fates, which disheartens those plagued by misfortune.
The truth of this letter seems solidified by the postscript, which politely asks Stiles to keep their communication private. It casts the letter in an even more intimate light one which separates Franklin’s private beliefs with his role as a political figure, whose declarations are carefully analyzed. His final declaration, that he supports a variety of denominations that endeavor to impart good, indicates he is not a petty man but one who supports noble actions regardless of the term given to their form -- quite a freethinking and admirable philosophy in my book.

This image is kind of irrelevant but we’ve been talking so much about belief, and I’m an avid X-files fan :)