I think it can be possible to discuss most religion or absence thereof without getting personal, by responding to the theology or reasoning, and not the individual, and without implying the other is an idiot.

All bets are off when religion starts preaching that some humans have less value than others, as for example the reported belief (which I am not sure is true) in Mormonism that a husband must invite his wife into heaven, or the insistence of some organized religion, such as Roman Catholicism, that women are unworthy of being priests, or Islamic instructions for when and how to beat your wife. Protestant Christian hands are not clean in this regard, particularly in the past, and there are still echos. Paul, IMO, has a lot to answer for in this regard, with his insistance on male heads of households and the silencing of women in churches.

I respect believers who are able to admit the faults of their religions, and are willing to try to remedy them.