No longer interested in death and sin (6)
I believe the answer is:
offend
'sin' is the definition.
(I've seen this before)
'no longer interested in death' is the wordplay.
'no longer interested in' becomes 'off' (I am not sure about this - if you are sure you should believe this answer much more).
'death' becomes 'end' ('end' can be a synonym of 'death').
'off'+'end'='OFFEND'
'and' is the link.
Can you help me to learn more?
(Other definitions for offend that I've seen before include "Cause to feel hurt" , "Do wrong or cause resentment" , "tread on someone's toes?" , "Upset; transgress" , "Cause affront or do wrong" .)