This is where there's a critical, vital split: K believes Jesus, trusts Jesus, trusts Vrenille.

He doesn't believe this concept that Jesus is presenting to him. He does not believe that he alone, his protest alone, is enough to stop anything from happening. He does not believe that his discomfort, his unease, makes a difference at all to something he's not even involved with.

And he has no idea how to reconcile these two things, so he falls silent instead.