Change church platform we hear (5)
I believe the answer is:
alter
'change' is the definition.
(I know that change can be written as alter)
'church platform we hear' is the wordplay.
'church platform' becomes 'altar' (I've seen this in another clue).
'we hear' indicates a 'sounds like' (homophone) clue.
'altar' sounds like 'ALTER'.
(Other definitions for alter that I've seen before include "Alert to change" , "Revise" , "Adapt" , "Change, make different" , "shift" .)