Perform turns because of God (4)
I believe the answer is:
odin
'god' is the definition.
(Norse god)
'perform turns because' is the wordplay.
'perform' becomes 'do' (both can mean complete an action).
'turns' says the letters should be written backwards.
'because' becomes 'in' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'do' reversed gives 'od'.
'od'+'in'='ODIN'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for odin that I've seen before include "mythological personage" , "Chief god of Scandinavian myth" , "divine figure" , "Supreme god of war in Norse mythology" , "Old Scandinavian" .)