If you want to re-frame any arguments that you have with the religious right, so that it feels that you aren't being talked to from a position of religious (if not moral) superiority, you could do worse than read this book.
The biggest problem now is that it's 5 or 6 years old now (and it's got an American focus), so it's possible that the examples he uses are out of date (and have an American focus), but that doesn't change the basic strength of the argument that Wallis makes.