Criminal pair I found in religious group (7)
I believe the answer is:
culprit
'criminal' is the definition.
(I've seen this before)
'pair i found in religious group' is the wordplay.
'pair' becomes 'pr'.
'found in' means one lot of letters goes inside another.
'religious group' becomes 'cult' (I've seen this before).
'pr'+'i'='pri'
'pri' going into 'cult' is 'CULPRIT'.
(Other definitions for culprit that I've seen before include "he should have conviction" , "The person to blame, the guilty one" , "Criminal" , "Perpetrator of a wrongdoing" , "One perpetrating crime" .)