Upbeat church with extremes of inner purity (6)
I believe the answer is:
chirpy
'upbeat' is the definition.
(chirpy means cheerful or upbeat)
'church with extremes of inner purity' is the wordplay.
'church' becomes 'ch' (common abbreviation).
'with' is a charade indicator (letters next to each other).
'extremes of' suggests removing the centre (only the letters at the extremes of the word).
'purity' becomes 'py' (I can't explain this - if you can you should believe this answer much more).
'inner' with its centre removed is 'ir'.
'ch'+'ir'+'py'='CHIRPY'
Can you help me to learn more?
(Other definitions for chirpy that I've seen before include "Lively and cheerful like sparrow" , "Lively and perky" , "Happy - like a bird?" , "Perky, like a bird?" , "Lively and merry" .)