Belief in sacred office (5)

I believe the answer is:

credo

'belief' is the definition.
(credo is a kind of belief)

'in sacred office' is the wordplay.
'in' indicates a hidden word.
'CREDO' can be found hidden inside 'sacred office'.

(Other definitions for credo that I've seen before include "Set of principles" , "Words of believer" , "Mass movement" , "set of ideas" , "piece of sacred music" .)

I've seen this clue in The Globe and Mail and The Telegraph.

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