Driving out evil energy, replacing nothing troubling (10)
I believe the answer is:
exercising
'nothing troubling' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'driving out evil energy replacing' is the wordplay.
I cannot quite understand how this works, but
'evil' could be 'sin' (synonyms) and 'sin' is found within the answer.
'energy' could be 'e' (physics symbol as in E=mc2) and 'e' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for exercising that I've seen before include "activity in gym?" , "training" .)