It doesn't matter because that fact overrides his point; why? because without Jesus everything is moot, useless, futile… death.
Only in the light of God does anything we do have real purpose, and that includes both nation-building (or separation) and attempting to obtain justice — which was Jefferson's point. That our first founding document places this in the forefront and builds its case for separation from Britain on that truth, making it foundational to the argument, is a good place to start and quite likely the reason it's stood the test of time so well.
Your credulity is touching. I can promise you that politics in the 18 th century was every bit as given to special pleading as our own or any other time.
“How is it that we hear the loudest yelps for liberty from the drivers of Negroes?”