I'd like to add to sharondoyle37's armor interpretation:
I agree, but I see it even more specifically to mean a shirt of mail armor (good defense against slashes, but often pierced by a strong enough blow). Religion may also stand for morality in this case, which would make sense with the two put together; little things here and there may not affect one's integrity much, but a single harsh blow easily challenges it.
I'd like to add to sharondoyle37's armor interpretation:
I agree, but I see it even more specifically to mean a shirt of mail armor (good defense against slashes, but often pierced by a strong enough blow). Religion may also stand for morality in this case, which would make sense with the two put together; little things here and there may not affect one's integrity much, but a single harsh blow easily challenges it.