Formal account of The Epistles, for example, in New Testament (9)
I believe the answer is:
statement
'formal account' is the definition.
(I've seen this before)
'new testament' is the wordplay.
'new' is an anagram indicator.
'testament' with letters rearranged gives 'STATEMENT'.
'of the epistles for example in' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for statement that I've seen before include "Announcement, issued by the bank say" , "Spoken or written declaration" , "Declaration of facts" , "Financial summary" , "Document showing credits and debits" .)