I don't buy that lying requires believing the lies even a little bit. Internalization may be important, but understanding religious thought and being able to speak about it convincingly doesn't require belief by any means.

It seems transparent that bad liars are exhibiting stress tics rather than trying to protect their internal narrative given the techniques for becoming a better liar (i.e. relax, practice, be confident) and the similarity to nervous people telling the truth when they're worried they'll get in trouble for it anyways (in the face of interrogation, for instance).