[possibly worth noting I am as cynical about politics. Suppose Americans found a "true" first version of the Constitution that clearly outlawed private citizens gun ownership * (versus miiltia). Wouldn't most gun advocates simply ignore / explain away that text? Thought experiment also requires the pretense that the differences were due to transcription changes, not actual belief changes]

* instead of "A well regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed," imagine it read, "Private citizens may own firearms if and only if, and while registered and paid entirely by a state-run militia, may access guns, but cannot use them except in their active attempts to overthrow a tyrannical government."

This would be pretty hard to arrange, seeing as:

We have the original source texts of the Constitution and the Bill of Rights, see http://www.archives.gov/exhibits/charters/charters_downloads...

Compare to the New Testament, which per my limited study wasn't immediately committed to writing, and several centuries later the Church had to decide which books and which versions were canonical.

Then there's the translation problem, the original is in the common dialect of Greek from 300BC to 300AD per Wikipedia. You can read the above copy of the Bill of Rights (in person if you make the trip to D.C.) and the only issue is how the definition of words have changed (militia) or have had additional connotations added (regulated).

We also have original source texts explaining the context and details that went into drafts and then final versions, e.g. the initial justification clause, common in state constitutions of the time, was a sop thrown to the subset of the founders who were justifiably suspicious of centralized and especially standing armies, but were overruled by military leaders like George Washington, who, of course, won the Revolutionary War with the latter sort of army and wasn't at all fond of the militia system for those sorts of extremes.

Then there's all the contemporary records that make it clear that to our Founders the right to self-defense was a natural and unalienable right; compare the language of the 2nd to the language of the 1st, which was much more limited. Getting back to religion, it starts:

Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof....

Only the Federal government is constrained (prior to the 14th Amendment), it certainly wouldn't have been accepted by states like Massachusetts which had an official state (established) religion at the time. Per https://en.wikipedia.org/wiki/State_religion#Former_state_ch...

- The colonies of Plymouth, Massachusetts Bay, Connecticut, New Haven, and New Hampshire were founded by Puritan Calvinist Protestants.

- The colonies of New York, Virginia, North Carolina, South Carolina, and Georgia were officially established under the auspices of the Church of England.

- The Colony of Maryland was founded by a charter granted in 1632 to George Calvert, secretary of state to Charles I, and his son Cecil, both recent converts to Roman Catholicism. Under their leadership many English Catholic gentry families settled in Maryland. However, the colonial government was officially neutral in religious affairs, granting toleration to all Christian groups and enjoining them to avoid actions which antagonized the others. On several occasions, low-church dissenters led insurrections which temporarily overthrew the Calvert rule. In 1689, when William and Mary came to the English throne, they acceded to demands to revoke the original royal charter. In 1701, the Church of England was proclaimed, and in the course of the 18th century Maryland Catholics were first barred from public office, then disenfranchised, although not all of the laws passed against them (notably laws restricting property rights and imposing penalties for sending children to be educated in foreign Catholic institutions) were enforced, and some Catholics even continued to hold public office.

- The Province of Pennsylvania was founded by Quakers, but the colony never had an established church.

- The Province of New Jersey, without official religion, had a significant Quaker lobby, but Calvinists of all types also had a presence.

- Delaware Colony had no established church, but was contested between Catholics and Quakers.

- The Colony of Rhode Island and Providence Plantations, founded by religious dissenters forced to flee the Massachusetts Bay colony, is widely regarded as the first polity to grant religious freedom to all its citizens, although Catholics were barred intermittently. Baptists, Seekers/Quakers and Jews made this colony their home. The King Charles Charter of 1663 guaranteed "full liberty in religious concernments"

Per a following table, Connecticut and Massachusetts retained their established religions for 2-3.5 decades, and New Hampshire and South Carolina for a couple of years after the Constitution was ratified.

Moving to interpretation, if you believe self-defense et. al. are natural, unalienable rights, the 2nd Amendment merely acknowledges that, and its current near total abridgment is meaningless outside of what various governments believe they can, and indeed do.

By that, I mean that while Heller and McDonald say we have a right to keep a gun available for self-defense in the home, D.C. and NYC can and do effectively forbid this, and there's no prospect that'll change for NYC, while the court cases in D.C. look to drag on for many more years (Chicago's ban got zapped by McDonald).

But then there's that pesky "and bear arms" bit, not covered by the Supremes except in the context of your home (yep, D.C. forbid that), and not recognized outside of the 7th United States courts of appeals (i.e. Illinois) or by the Supremes, and being litigated in the 9th, where it will probably lose, and D.C. where it's dragging on like mere ownership.

Anyway, the point of the above three paragraphs of details going into the weeds for most people is that even based on a much more solid textual and contextual foundation, the simple English words of the 2nd Amendment in practice allow for about as much interpretation as we see in practice happening with the Bible. Except, of course, the state has bowed out of the game pretty much everywhere in formerly Christian world.