Shaykh al-Islām Ahmad ibn Taymiyyah—may Allah sanctify his soul—was asked about a man who said:

“If Muslims follow the authority of others, and Christians and Jews do likewise, on what grounds can Christians and Jews be refuted and their doctrines invalidated under these circumstances? What is the conclusive proof that establishes the truth of the Muslims’ position and refutes the falsehood of the unbelievers?”

He replied—may Allah be pleased with him:

Praise be to Allah. Whoever says this is lying and misguided in this assertion. Blameworthy imitation consists of accepting another person’s statement without proof, as did those of whom Allah said:

“And when it is said to them, ‘Follow what Allah has revealed,’ they say, ‘Rather, we will follow what we found our forefathers following.’”

Allah Most High says:

“Even though their forefathers understood nothing and were not guided?”

And He says:

“Indeed, they found their forefathers astray.”

“So they hastened to follow in their footsteps.”

There are many similar passages in the Quran. Thus, whoever follows the religion of his forefathers and predecessors out of ingrained habit and abandons following the truth