In a pious way, I'm reformed by its moralising (6)
I believe the answer is:
homily
'reformed by its moralising' is the definition.
I can't judge whether this defines the answer.
'in a pious way i'm' is the wordplay.
'in' means one lot of letters goes inside another.
'a pious' becomes 'holy' (both mean religious).
'way' becomes 'm' (I am not sure about this - if you are sure you should believe this answer much more).
'i'm' becomes 'i' (I've seen this in other clues).
'm'+'i'='mi'
'holy' enclosing 'mi' is 'HOMILY'.
Can you help me to learn more?
(Other definitions for homily that I've seen before include "Lecture on a moral topic" , "Sermon on a religious topic" , "Address" , "Edifying discourse" , "Moralising lecture" .)