The Bible recommends many social laws which we laugh off in the 21st century as bizarre; but they had a valid reason d'être during the times this book was written. The Koran urged men to take more than one wife because the gender ratio at the time, in this particular region of the world, mandated a solution that helped protection of women who vastly outnumbered men (*). Incidentally this in itself shows that those books were written by humans, and not God (more exactly are not the "word of God" as some would have us believe -- otherwise, given how badly those books age from one millennial to the other, that would make God very stupid). They were written by humans who cared about social situations/issues in a particular moment in time, in a particular small area of the world, and within a particular cultural settings (the latter far to be universal). The Chinese, for instance, who at the time the Koran was written, were far more socially and scientifically advanced than the Arabic, would have laughed at the Koran, and maybe they did.(*) Incidentally, I had to explain to a Muslim girl recently that actually the ratio of men/women in the world (which is itself the reflection of the human spermatogenesis and vaginal chemical selection) is in the range 101-105 boys to 100 girls, or a ratio boy/girl of just a bit more than 1. If we decide to pair male and female through the social construct know as marriage, this means that out of 100 women, most women should marry one guy and few women should marry two guys (you can find the exact numbers by solving the corresponding first order linear equation). In practice though, men tend to engage in more dangerous activities and sometimes die before their time, bringing back the men/woman ratio closer to 1, which means that everybody gets to marry exactly one person of the opposite sex. (Leading to think that the exact observed number of born babies per gender is probably the result of evolutionary selection). Unfortunately, this Muslim girl was so brainwashed about the "right" of men of her neighborhood to marry more than one woman that she wrongly believed all her life (because she is not totally stupid and simply followed the "logical conclusion") that there must be more women than men in the world.
Moving to the US constitution, the Founding Fathers weren't idiots. The 2nd Amendment was written at a time when a proper organized law enforcement was still not in place in the newly born country. Individuals and families were yet at the mercy of violent looters. Also, and this is very important, the second amendment was written at the time it took one minute to recharge a gun with a single bullet. Under those conditions who would think that the second amendment was actually meant to protect people carrying semi-automatic rifles to public places (which is unfortunately allowed in some US states) ? The answer to this question is simple: Idiots. The same who go to church (or any other "place or worship") every week, or lobbyists working on behalf of the gun industry.
The ability of some people to live by outdated texts written hundred, if not thousands of years ago, to maintain their own internal mental fantasy-land, really baffles me. Their attitude is insulting at best.