What does " I cannot follow them" mean in E.M. Forster's My Wood?
Sometimes the Gospels proceed further and say with Tolstoy that property is sinful; they approach the difficult ground of asceticism here, where I cannot follow them.

I'm not sure whether it means "I do not agree with them" or "I do not understand them" in this usage.

Question

What does " I cannot follow them" mean in E.M. Forster's My Wood?
Sometimes the Gospels proceed further and say with Tolstoy that property is sinful; they approach the difficult ground of asceticism here, where I cannot follow them.

I'm not sure whether it means "I do not agree with them" or "I do not understand them" in this usage.

Answer

I think it means "I do not agree with them" - or even more "I choose not to do what they say". 
I can understand your confusion though - I had to read it a couple of times before I understood.