There are many famous Halachic issues involved in removing a beard. The Sefer Hadras Panim Zakan brings literally hundreds of Poskim [Halachic authorities] that discuss these issues. It is not possible to present all the opinions on this subject, so we will focus on the opinion of the third Lubavitcher Rebbe, the Tzemach Tzedek , which is the authoritative opinion as far as Lubavitcher Chassidim are concerned. The Tzemach Tzedek did not just regard the discussion about wearing beards as an academic matter, in fact, he waged many battles for its observance. The Russian Czar Nikolai I wanted to institute a policy making it mandatory for all Jews to shave. The Tzemach Tzedek exerted himself and through Mesiras Nefesh [self-sacrifice] was able to get this decree revoked.
A summary of the Tzemach Tzedek's opinion follows:
A. It is forbidden to remove the beard through scissors, (even with those that do not resemble a razor) or through depilatories (hair removal through medicine).
This is due to the law of Payos Hazakain, "Neither shall you mar the corners of your beard."
B. Those who remove their beards transgress the Torah law of, "A man shall not wear the garment of a woman." Some authorities hold that this brings with it a punishment of Malkos (lashing). This reason applies even to those who cut their beard with a scissors.
C. Removing the beard without a razor can lead one to remove the beard with a razor - leading to a transgression of Torah law. Furthermore, using a scissors to cut the beard violates the reason that underlies the prohibition (Taam Hamitzvah ).
D. The hairs of the beard contain a high degree of holiness as is taught in Tanach and the words of the Rabbis.
E. The Rabbis from the time...