Shaykhul-Islām Ibn Taymiyyah رحمه الله stated:

“Anyone who takes a Shaykh or Scholar to be one who is followed in everything that he says and does, having an alliance for (those who are in) agreement with him and enmity for (those who are in) opposition to him other than Messenger of Allāh ﷺ, this person is a misguided innovator who is outside of the (correct practice of the) Book and Sunnah.”

[Jāmi’ Al-Masāil 7/466]

‏قال شيخ الإسلام ابن تيمية – رحمه الله-:

«كلَّ من اتخذ شيخًا أو عالمًا متبوعًا في كل ما يقوله ويفعله، يوالي على موافقته ويعادي على مخالفته غير رسول الله ﷺ، فهو مبتدع ضالَّ خارج عن الكتاب والسنة»

[جامع المسائل (7/ 466)].