Anti vaccine rhetoric has an extremely high correlation to religious people. The commentor was speculating about how these people in the past would have felt about the anti vaccine people today. It's a valid question. People back then didn't have access to information or access to much real hope; it's not surprising they were religious.
And just eat in general. My goodness sometimes I'm so surprised, I'll be feeling terrible (usual for me) and I'll realize I haven't eaten in a long time and take like one bite of something and instantly my headache and possibly fatigue are significantly better.
If someone stumbles across something like this and is influenced by it, I think odds are extremely great that they were already of a similar mindset. If it preached violence or bigotry or anytime I'd see more of an issue.
I read things like this (or try to) and I think, just let him be. The most powerful thing that can help someone is what they think works for them. There's no need to tear it down if it's not harmful to others.
I worship the lovely soup.