Islam is all about proofs from Quran and Sunnah..for that u need proper education..no degree or nothing..but learn from proper knowledgeable individuals or from institutions..the professor doesn't even have a beard..
The Beard according to the Great Imams of Jurisprudence
Hanafi
Imam Muhammed (R.A.) writes in his book "Kitabul Aathaar" where he relates from Imam Abu Hanifa (R.A.) who relates from Hadhrat Haytham (R.A.) who relates from Ibn Umar (R.A.) that he (Ibn Umar) used to hold his beard in his hand and cut off which was longer. Imam Muhammed (R.A.) says that this is what we follow and this was the decision of Imam Abu Hanifa. Therefore, according to Hanafies, to shorten the beard less than a FIST LENGTH is HARAAM and on this is IJMA (concensus of opinion).
Shafi'i
Imam Shafi (R.A.) in his Kitabul Umm states, "To shave the beard is HARAAM." (Shari Minhaj dar Shara Fasl Aqueeqa).
Maaliki
Shekh Ahmad Nafarawi Maliki in the commentary of Imam Abu Zayed's booklet states, "to shave the beard is without doubt haraam according to all Imams." It is also mention in "Tamheed" which is a commentary of "Muatta" (Sunnan Imam Malik (R.A.)) that to shave the beard is HARAAM and among males the only ones to resort to this practice (of shaving) are the HERMAPHRODITES (persons who possess both male and female features and characteristics).
Hanbali
The Hanbalies in the famous Al-Khanie'a Hanbali Fatawa Kitab state that "to grow the beard is essential and to shave it is HARAAM." Also in the Hanbali Mathab books "Sharahul Muntahaa" and "Sharr Manzoomatul Aadaab", it is stated "The most accepted view is that it is HARAAM (prohibited to shave the beard).