No, it's their premise that religious text cannot be used in forming government policy. Otherwise, we would, in all fairness, be expected to quote the Koran and other religious texts as well.
Yours,
panther33
Why is it wrong? Because religious texts are constantly in use in formulating public policy! Even today, by every level of legislative, judicial and executive body I know of.
Take the current Supreme Court -- they have considered arguments from the Jewish Talmud in a recent death penality case.
Or take Thangsgiving! A Federal, a National, Holiday. As in "Holy Day". A day DECLARED by Presidents, Judges and Legislators to be put aside for a "religious" purpose.
Did your "friends" celebate that? Ask them? Ask them if they "Thanked Darwin" at the start and/or end of the meal.
Why is it foolish? It is foolish of you to waste time arguing with people whose "rules of evidence" are so narrow and restrictive some prejudicial outcome is assured before any argument starts. They kow it too! They want to make a fool of you.
In my book, such mean or vain-glorious attempts to make others the fool are the deepest indication that those who so attempt are fools themselves.
Why is it imbecilic? It is most assuredly so dumb, so empty of intellectual scrutiny, so unsustainable a premise in the face of any level of scholarship (that means reviewing existing texts and researching history) to be imbecilic.
Secularism, darwinism, scientificism and such are ALL religious belief systems. That there practitioners may refuse to be label "religious" is of no import in an absolute sense.