He hunted revolutionary military force involved in murder (6)
I believe the answer is:
nimrod
'he hunted' is the definition.
(hunter in the Bible)
'revolutionary military force involved in murder' is the wordplay.
'revolutionary' says the letters should be written backwards.
'military force' becomes 'RM' (Royal Marines).
'involved in' means one lot of letters goes inside another.
'murder' becomes 'do in' ('do in' can mean to kill).
'rm' placed into 'doin' is 'dormin'.
'dormin' in reverse letter order is 'NIMROD'.
(Other definitions for nimrod that I've seen before include "One of Elgar's Enigma Variations" , "OT hunter" , "Elgar Enigma variation; D minor (anag.)" , "Skilful hunter (Genesis)" , "Old hunter" .)