Poor patron taking exam for believer (10)
I believe the answer is:
protestant
'believer' is the definition.
'poor patron taking exam' is the wordplay.
'poor' indicates an anagram.
'taking' means one lot of letters goes inside another.
'exam' becomes 'test' (synonyms).
'patron' with letters rearranged gives 'proant'.
'proant' placed around 'test' is 'PROTESTANT'.
'for' is the link.
(Other definitions for protestant that I've seen before include "Opposing" , "Martin Luther, for instance" , "expressing dissent" , "Member of a church separating from Rome at the Reformation" , "Member of church founded on the principles of the Reformation" .)