We have in our midst "Constitutional Originalists", who don't like where the country has gone, and want to return to its roots. For instance, why do we operate on this "wall of separation between church and state", when it's not literally in the Constitution?
I can agree with one point - I think the default interpretation of any text is the literal interpretation. That includes the Bible.
If you're going to argue that this doesn't mean what it literally says:
"If a man has sexual relations with a man as one does with a woman, both of them have done what is detestable. They are to be put to death; their blood will be on their own heads." (Leviticus 20:13 NIV)... and instead means that we should "hate the sin, and love the sinner"... you've got a burden of proof to meet, as to why the literal understanding is incorrect. That's not abnormal, though. We abandon literal readings all the time, in favor of better contextual evidence... but that context needs to be furnished.
When it comes to the Constitution, it's key to realize that, as written, many of the amendments have situations where they are internally contradictory, and thus, a simply literal interpretation cannot feasibly resolve the problem.
Take the first amendment (emphasis mine):
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.What if a particular religion has a practice of abducting people off the street, and performing human sacrifices? According to the First Amendment, Congress shall make no law that prohibits that particular exercise of religion.
So what gives? Clearly, we understand that this would be horrifyingly illegal to allow.
Sometimes, rights conflict. My right to due process, to be free from cruel and unusual punishment, free in my persons, etc (a smattering of other rights), would be conflicting with the other person's exercising of his/her religion. Human sacrifice is an absurd example, but we can easily change it to something more common, like religions committing fraud, child rape, false imprisonment, etc.
Do the rights of the religion trump everyone else's rights? Of course not.
On a basic level, when we're trying to resolve a conflict between Right A and Right B, we defer to which one is less imposing - your rights end where my rights begin.
How do we do this when the Constitution clearly forbids it? The Constitution created a judiciary, whose job it was to interpret and implement the law... meaning, they have to figure out the best, most reasonable understanding of the spirit of the Constitution's amendments and context.
We establish Case Law, that extends our understanding of what the Constitution says, and the best interpretations when it comes to practical implementation. This is mandatory to actually adhering to what would otherwise be an internally inconsistent literal interpretation of the Constitution.
We decided that being religious isn't a free pass to commit fraud, because we decided the First Amendment doesn't reasonably cover that particular freedom... and that the fewest rights (whether constitutional or via subsequent State/Federal law) of others are being trampled.
The secular notion of the separation between church and state is one such practical interpreted understanding. When we read what the Founding Fathers wrote, what they thought, as well as their contemporary context, it's abundantly clear that they wanted a government that kept it's dirty paws out of religion, and religion out of government (and why the likes of Barton are feverishly rewriting history to make this not so).
The First Amendment just wasn't written all that clearly. What does "religion" mean? Or "congress"? What did they mean by those words? They couldn't fully foretell how the future would unfold for the country, so they proactively gave us the power to change, if we needed.
Regardless of what the Founding Fathers wanted, it seems clear (to me, anyway), that a secular nation is the healthiest - it's the best, most reasonable application of the Constitution, that benefits everyone equally, the most.
It's the best way to resolve conflicting rights. We both have a right to a government that represents us. You don't get to use my government to proselytize your religion. Your rights don't trump mine.