If your aim is to convince her of a single point about a scripture applying to Satan, restrict your response to that.
If your aim is to both convince her of ^that point and, in doing so, chisel away at a blockade of critical thinking, restrict your response accordingly.
If your goal is to vent your frustrations with the cult without regard to preserving a relationship with this individual, post your original reply (which is a laundry list of complaints).
Either one is fine, depending upon the