بـسم الله الرحمن الرحيم
Narrated Buraida رضي الله عنه: Allāh's Messenger ﷺ said:
“Al-Qudāt (judges) are of three types, two of whom will go to Hell and one to Paradise. The one who will go to Paradise is a man who knows what is right and and gives judgement accordingly; but a man who knows what is right and does not give judgement accordingly and acts unjustly in his judgement will go to Hell, and a man who does not know what is right and judges people with ignorance will go to Hell.” [Reported by Al-Arba'a, and Al-Hākim graded it Sahih (sound)]
This Hadith states two points. First, a person who does not know the truth and another person, who does not act upon the truth despite being aware of it, such persons shall equally be condemned to Hell-fire. It means that the knowledge without action has no value. Secondly, the possibility of committing a judgemental error exists for anyone who exercises a judgement. Had it not been so, people would not have been divided as such and making of such fine distinctions among them would have been out of place.
Source: Bulugh Al-Maram p. 491, under The Book of Judgement|Compiled by:Al-Hafiz Ibn Hajar Al-Asqalani, DARUSSALAM.