I had a patient recently who suddenly developed an irregular heart beat. There are lots of things that could cause this, including many medications. I asked the patient what medications she was taking and she said none. A few minutes later, looking around her room, I saw a large tub filled with pill bottles. I pointed to them and asked her what they were. She said, "Oh, just my herbals." I told her that herbs are made of chemicals and some of them can interfere with her heart rate (or with the blood thinners and heart rhythm medications we were giving her). She said, "No, they aren't chemicals. They are natural." I explained how many of our modern medicines comes from plants. She smiled, agreed wholeheartedly and said, "Yes, plants are natural medicines." I said that she was right and she should realize that medicines, even natural medicines, can have side effects. She replied, "No, medicines you give me have side effects because they are man made. Natural medicines are made by God and He has made sure that they don't have side effects." I knew I had no chance to convince her why what she was doing was dangerous. I looked through her box of supplements and didn't recognize most of them, but there were some known to be stimulants and others known to interact with blood thinners. I told her not to take those few (5 of the more than 30). She declined saying she trust's God's medicines more than mine. I spent a few minutes explaining why we were so worried, but got no where. When I left she said "God bless you." Mixing quackery with religion makes a dangerous thing deadly.
I'm not too surprised that quackery and religion go hand in hand. With both you are convinced that you know the truth, that whatever else is out there is a lie and if there is a conflict between the two, you are always right. With both, there is no critical thinking. With both, rather than reasoning with someone trying to convince you otherwise, you get offended. With both, you bend over backwards trying to ignore the obvious deficiencies with what you believe in.