Religious devotion (5)
I believe the answer is:
piety
'religious devotion' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for piety that I've seen before include "Devotion to religious principles" , "Dutiful devotion" , "Attentive religious practice" , "An unthinkingly accepted belief" , "paying proper duty" .)