Respecting Other Religions
What got me thinking about this topic was a discussion with a friend of mine about George Harrison's "My Sweet Lord." Is there something to be said about the guy expressing his religion and longing to be close to God, or is it all silly anyway, because he's not Jewish and his religion is false?
I don't think there's anything intrinsically signficant about a non-Jew following their religion. In most cases, it's avoda zara, so what good does it do for us? What good does it do for the world?
But that said, there's something to be said for the effects of religious non-Jews, in two ways:
1) Most religious non-Jews generally will follow the seven mitzvos of Bnei Noach. It's unclear whether those mitzvos have a transendental positive effect on the world as when Jews do mitzvos, or whether they're merely meant as a civil code so that the nations don't live in chaos. (According to the latter understanding, it's a bit unclear where the prohibition on blashphemy fits in; according to the former, why is there no inyan of "arvus" when it comes to the seven mitxvos? But ANYWAY....)
And even if their mitzvos don't have a spiritual positive effect, their religious practices still make a difference. After all, the Jewish world is strongly influenced by the non-Jewish culture. For example, the fact that divorce is no longer taboo in the non-Jewish world has lead to an increase in divorces in the frum community. And in the 1970's, when everyone including Jimmy Carter was becoming a born-again Christian, many baalei tshuva returned to the fold.
Of course, in the case of the Muslims, their return to fundamentalism has not done much good to the world. But in moderation, religious practice is not problematic, especially in America, where the courts preserve religious freedom.
2) The other benefit from the non-Jewish religious practice is that we can take some mussar from it. Perhaps, for example, we can look at a song like "My Sweet Lord" and think about whether we've felt a longing to be close to God. And perhaps from their search for meaning in life, we can take a lesson and try to make the routine practices of Judaism more meaningful. I'm not saying that we should study the world's religions in-depth to get all sorts of lessons from them, but there are certainly things we can pick up from them, even from passive observation.
So I don't see how their worshipping whatever they worship makes the world a better place. But their observance of their laws certainly is not a bad thing. And let us not forget Ben Zoma's statement - "Who is wise? He who learns from all people."