I do attempt to point out discrepancies. The Da Vinci code discussion alone was an eye opener. It is a movement growing and gaining in popularity in our parish, to the point I think I might need to find another. Although I do more frequently attend a different one, but now they've consolidated schools and 'standardized' worship 'space' - ugh - spreading their ills. A lot of parishioners have left altogether in the last decade.
They are using the same tactics they used to take over the Episcopal Church. Stay with it. Continue to state correct doctrine so that the waverers/confused among them will have a chance to listen to the Truth. Don't expect argument to win over the true liberals, however.