Jack may work on this ecclesiastical point (7)
I believe the answer is:
steeple
'point' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for steeple that I've seen before include "Jack up this?" , "point" , "that the church may be under" , "Pet eels (anag)" , "Tall tower with spire on top of church" .)