Ibn ‘Uthaymeen said:
“All the Salaf called to Islaam and to unite upon the Sunnah of Allaah’s Messenger (sallallaahu alayhi wa sallam), and they did not declare astray anyone who differs with them (in a certain issue) because of (a different) interpretation (Taweel), except in matters of Aqeedah, because they considered him, who differed in Aqeedah, as astray.
But, in our time, some who took the path of Salafiyyah consider astray everyone who differs from them, even if the truth were to be on his side. And they took a Hizbee (partisan) Manhaj, just like the other Hizbs (parties), who divide the religion. This (their way) must be rejected and not be approved of.”
Excerpt from his book, “Liqaa-al-Baab al-Maftooh”