Again perform after confirming first belief statement (5)
I believe the answer is:
credo
'belief statement' is the definition.
'credo' can be an answer for 'statement' (I've seen this before). I am unsure of the 'belief' bit.
'again perform after confirming first' is the wordplay.
'again perform' becomes 'redo' ('do' can be a synonym for 'perform' so perhaps 'redo' is OK for 'again perform').
'after' is a charade indicator (letters next to each other).
'confirming first' becomes 'c' (1st letter of 'confirming').
'redo' after 'c' is 'CREDO'.
Can you help me to learn more?
(Other definitions for credo that I've seen before include "System of principles" , "conviction" , "Faith - I believe" , "Part of the service" , "Set of principles" .)