Shame, it turned into disbelief (7)
I believe the answer is:
atheism
'disbelief' is the definition.
(thesaurus)
'shame it turned' is the wordplay.
'turned' is an anagram indicator.
'shame'+'it'='shameit'
'shameit' with letters rearranged gives 'ATHEISM'.
'into' is the link.
(Other definitions for atheism that I've seen before include "Owed" , "Disbelief in gods" , "Disbelief in a god" , "Non-belief in God" , "A lack of faith" .)