That scripture does not have anything to do with spiritual blindness and deception. It has to do with sin. We have all sinned so none of us can cast the first stone, but we are not all spiritually deceived as Trapper is. Some of us can see clearly as our spiritual eyes have been opened. Nevertheless, I will leave you alone to follow whomever you wish regardless of their level of deception. It's your soul, not mine.
Let them alone: they be blind leaders of the blind. And if the blind lead the blind, both shall fall into the ditch.