David Cameron’s reply to this perverse little MP SOB should simply be that Parliament does not in the 21st Century dictate Church dogma, and that if the MP persists in this line of inquiry steps will be taken to remove him for irresponsible and inappropriate comments which are damaging to the true function of the civil government.
That would be an excellent way to deal with this particular situation. Put the guy on the defensive for attacking freedom of religion and the rule of law.