There's no way to break sinful fraud (9)
I believe the answer is:
imposture
'fraud' is the definition.
(imposture is pretending to be someone else)
'there's no way to break sinful' is the wordplay.
'there's no way' becomes 'ost' (I am not sure about this - if you are sure you should believe this answer much more).
'to break' is an insertion indicator.
'sinful' becomes 'impure'.
'ost' put inside 'impure' is 'IMPOSTURE'.
(Other definitions for imposture that I've seen before include "deception" , "Fraud" , "Trick" , "The assuming of a false identity" , "Assumption of a false identity" .)