Delight shown by member joining church (5)
I believe the answer is:
charm
'delight' is the definition.
(I've seen this before)
'member joining church' is the wordplay.
'member' becomes 'arm' (arm is a kind of member**).
'joining' means one lot of letters go next to another.
'church' becomes 'ch' (common abbreviation).
'arm' put after 'ch' is 'CHARM'.
'shown by' is the link.
(Other definitions for charm that I've seen before include "Make delighted" , "Something believed to bring good luck" , "Power of fascination" , "Bewitch or delight" , "Spell; ornament" .)