This worked for me
1. I do not find it reasonable to try to convince her that there is fault in her religion. It is her faith and I have mine.
2. I told her that I have issues but do not want to discuss about it directly. I proposed that I tell my views in a letter and she can read it at convenient time.
3. I wrote my letter, telling the whole thruth about my thinking and that I will still love and respect her. I encouraged her to respond with letter rather than taking risk for oral dispute.
4. She did respond after which we then had a discussion in stress-free setting.
CP