A good way of distinguishing texts that have attained scripture status – the Bible for Christians, the Qur’an for Muslims, the Founding Fathers’ writings for Americans, Das Kapital for Marxists – from ordinary texts is how political hacks treat them. Ordinary texts, people, events, etc., are viewed positively or negatively based on the person’s bias. For instance, a conservative will automatically view The Feminine Mystique negatively.
In contrast, scripture is universally revered within its target group, so that the writer will instead project his own views onto it. Hence the constant tug of war over who represents the ideals of the Founding Fathers as presented in 1776 better. It’s as if writers can choose one of several sources to appeal to: the facts, what the Bible says, what the Founders said, what Lincoln believed in, what MLK marched for.