As for their attitude, leave them to heaven. If do not hesitate to speak out in meetings to correct them in a fraternal way. If they obstinately refuse to hear the truth, then shun them.
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.