Shaykh Uthaimeen said, “We hold that when permissible disagreement occurs between the Muslims, and that is the type of disagreement in which ijtihaad has a place, then it is not allowed for the one who disagrees to call the person who opposes him misguided, or to declare him to be a faasiq, or to call him an innovator—for as long as it is an issue in which ijtihaad has a place, where the texts may imply this or that, then the opinion of either one of them which is based on his ijtihaad is not binding on the other.

And whoever wants his opinion to be binding on others—then he has assumed for himself the station of Prophethood and Messengership, and claimed infallibility for himself.

And that is why a person should repeatedly say: ‘O Allaah! Lord of Jibraa’eel, Mikaa’il, and Israafil, Originator of the heavens and the earth, Knower of the unseen and the seen! You judge between Your slaves concerning that wherein they differ. Guide me concerning that wherein they differ of the Truth by Your Leave, for You guide whomsoever You will to the Straight Path.’” [Muslim]

Majmoo’ Fataawaa wa Rasaa’il Fadilatish-Shaikh Muhammad ibn Saalih al–’Uthaimeen, vol. 27, p. 238.

Taken from http://giftsofknowledge.net/category/methodology/