The Founders believed-- and so do I--that we are endowed by our Creator with life and liberty. The Founders also knew that, beyond that broad level of generality, religions disagree sharply with each other about exactly what is "God's will." They therefore set up a government under which the people, through their elected representatives, can enact laws without having to seek the permission of any clergy who purport to speak for God. Their wisdom in that regard is amply demonstrated by the experience of other societies-- ranging from Calvin's Geneva to Islamic Iran-- which have given mortal men who claim to know "God's will" the power to make laws.
That’s a bit underhanded, the seeking the permission of clergy part. The previous poster did say it was self-evident. This whole issue of the proper mixture between religion and politics confounds me, honestly. Religion, so far as you have it, infuses itself in every part of your life. Which doesn’t mean it should dominate every part of your life, but no one has any idea in general how much or little it should dominate. Unless we’re talking the establishment if an official national church, or something, in which case we pretty much all agree.
I don’t believe in God, which isn’t to say I have no effective religion. I went to church every Sunday when I was a kid, and gave had to listen to church talk off and on randomly arround me since. So I’m used to it, but that doesn’t mean certain people, Glenn Beck for instance, don’t suddenly sound like mullahs sometimes.
It’s a matter of taste and tone, more than anything. If I was a militant atheist the previous poster might make me wretch. If I were you, apparently, I’d draw inferences about his reliance on specific advice from clergy, rather than rank marriage amongst things on “that broad level of generailty” which it was okay for the Founders to declare God’s will.
If you listen to people in previous centuries, even the deists, they can sound like the biblethumpinist revival tent hellfire preaching ecstatic prophecying theocrats since Savonarola. That’s a matter of tone and taste. To a great extent they thought differently. To another extent that’s just how they talked.