The redoubtable Peter Berger has a winning column on them.  A few years back I had one, but despite Berger’s plausible claim that “the power of the beard as a profane symbol of adult masculinity should not be underestimated,” my wife for some reason did not hold my beard in very high esteem. 

Berger’s post is prompted in part by the legal controversies involving the Amish beard cutting incident in Cleveland, now being tried as a federal “hate crime,” and the trial of alleged murderer Major Nidal Hasan in Fort Hood, Texas, who was ordered to shave his beard for trial.  Here is Berger’s beards and religion angle (but you really should not miss the rest):

Needless to say, religion is a particularly rich field for the beard as sacramental symbol. There are significant differences between Latin and Greek Christianity. Bearded priests have become the norm in Eastern Orthodox churches; in the Roman Catholic Church, while there are some monastic orders whose monks wear beards, secular priests are normally clean-shaven. I don’t know whether there are “grooming regulations” in either case, nor do I know of any in Protestant churches. Mormons stand out: Young men going out on their two-year missionary stints must be clean-shaven, as must students at Brigham Young University. Beards have become the trademark of Orthodox Judaism, though the Torah does not command them directly (Leviticus only has rules for shaping the beard). I would imagine that there are different deductions from these rules in the Talmud. Jews in mourning, while “sitting shive”, don’t shave and let the stubbles sit during this period. Sikhs are very intent on their luxurious beards. Many Hindu ascetics have beards, but that is not so much a symbol as the result of their having no possessions, not even a razor (they do beg—is there no pious barber who can donate a free shave?). I have no knowledge of Buddhist attitudes to facial hair. But of course we are most aware of the role of beards in contemporary Islam.  Beards are the male equivalents of female headgear. If young men in Turkey come out of the closet as Islamists and consequently drive their Kemalist parents crazy, their young sisters achieve the same result by covering their hair with the scarves that signify Islamic modesty. As far as I know, there is no commandment to wear beards in the Koran, though there is an authoritative tradition (hadith) according to which the Prophet Muhammad did issue such a commandment.

I promised that there would be no theoretical or practical conclusions. Let me just say this: There are very few “natural” symbols. (Though the lion may be a “natural symbol” of might, as against the mouse.) Beyond such clear cases, anything can symbolize anything. Symbols change over time. As to beards, often they symbolize nothing beyond themselves—as Freud did not say, but might have said: Sometimes a beard is just a beard. Beards have carried all sorts of symbolic freight. In the area of religion, it would be nice if beards symbolized moderation and tolerance.