Reforming priests carry on (7)
I believe the answer is:
persist
'carry on' is the definition.
(to persist is to carry on with something)
'reforming priests' is the wordplay.
'reforming' indicates anagramming the letters.
'priests' is an anagram of 'PERSIST'.
(Other definitions for persist that I've seen before include "Continue obstinately, don't give up" , "Persevere, hang on" , "Continue in spite of difficulty" , "Stripes (anag)" , "Pursue course doggedly" .)