I recently stumbled upon this interesting quote:
The genuine realist, if he is an unbeliever, will always find strength and ability to disbelieve in the miraculous, and if he is confronted with a miracle as an irrefutable fact he would rather disbelieve his own senses than admit the fact. Even if he admits it, he admits it as a fact of nature till then unrecognised by him.
from The Brothers Karamazov, page 31 of the 2004 Barnes & Noble Classics edition.
I appeal to you, brothers, to watch out for those who cause divisions and create obstacles contrary to the doctrine that you have been taught; avoid them. For such persons do not serve our Lord Christ, but their own appetites, and by smooth talk and flattery they deceive the hearts of the naïve. (Romans 16:17-18)