I think the vicar says that they were to be humble now, because of loss of fotune.

Then he goes on to say that:
Poor people 'get educated' to become callous (unfeeling) to the contempt that is shown to them.

In short - his family has not been educated to be callous(unfeeling) to treatment of contempt.

I think he is saying that that is what being 'humble' means - educated in being callous to the contempt shown.