Note, one is in church free from clerical doctrines (7)
I believe the answer is:
laicise
'free from clerical doctrines' is the definition.
The definition suggests a verb in its base form which matches the answer.
'note one is in church' is the wordplay.
'note' becomes 'la' (I've seen this in other clues).
'one' becomes 'I' (Roman numeral).
'in' indicates putting letters inside.
'church' becomes 'CE' (abbreviation for Church of England).
'is' going within 'ce' is 'cise'.
'la'+'i'+'cise'='LAICISE'
Can you help me to learn more?
(Other definitions for laicise that I've seen before include "Return to status before ordination" , "Of priest, reduce to non-clerical status" , "Remove from priesthood, reduce to secular state" , "Secularise, remove from clergy" , "Withdraw priestly status" .)