Get to give a sermon, but not quietly (5)
I believe the answer is:
reach
'get to' is the definition.
('reach' can be a synonym of 'get to')
'give a sermon but not quietly' is the wordplay.
'give a sermon' becomes 'preach' (I've seen this before).
'but not' indicates named letters should be taken away.
'quietly' becomes 'p' (p for piano and quiet).
'preach' with 'p' removed is 'REACH'.
(Other definitions for reach that I've seen before include "Grasp" , "Get as far as" , "Arrive at; extend to" , "Attain; extend to" , "Get to; extent" .)