Shaykhul Islam Ibn Taymiyah said:
Many of the people weigh the statements with the men (who said it) if he believes in regards to the man that he is great/honourable. Then they accept his statements even if they are false, (and are) in opposition to the book and the Sunnah.
Rather, he won’t even pay attention to/listen to the one who refutes that statement with the book and the Sunnah. Rather, he makes his companion as if he is infallible.
And if he doesn’t believe in regards to a man that he is great/honourable, he rejects his statements even if it be true. Thus he makes the one who utters the statement the means (i.e. the criteria) to acceptance and (i.e. or) rejection, without weighing (the statement with) the book and the Sunnah.
[Jaamiul Masaail 1/463]
Subhanallah an amazing statement! How many times do we advise certain people regarding certain individuals and they say “But he is a Shaykh and you’re not”, even if you were to bring him many evidences?!
As Imam Albani used to say, (not word for word):
One proof is sufficient for the person seeking the truth. As for the person of falsehood, not even one thousand proofs are sufficient for him.
Majid Jawed Al-Afghanee