Men in extremes of strife flipping love God (4)
I believe the answer is:
eros
'love god' is the definition.
(Greek god of love)
'men in extremes of strife flipping' is the wordplay.
'men' becomes 'or' (military abbreviation for Other Ranks).
'in' indicates putting letters inside.
'extremes of' means to remove the middle letters (only the letters at the extremes of the word).
'flipping' says the letters should be written backwards.
'strife' with its middle removed is 'se'.
'or' inserted into 'se' is 'sore'.
'sore' in reverse letter order is 'EROS'.
(Other definitions for eros that I've seen before include "God of love; life instinct (Freud)" , "One worshipped" , "Cupid, to the Greeks" , "Winged archer" , "Group of instincts" .)