Text rules announcing what could reduce the wages of sin? (6)
I believe the answer is:
syntax
'text rules' is the definition.
(grammatical structure)
I can't explain the remainder of the clue.
(Other definitions for syntax that I've seen before include "Rules governing formation of words into sentences etc" , "Rules governing the use of words" , "Verbal order" , "The rules governing words arrangements" , "Linguistic study" .)