Salvation Army, army with name for the Devil (5)
I believe the answer is:
satan
'the devil' is the definition.
('Satan' can be a synonym of 'devil')
'salvation army army with name' is the wordplay.
'salvation army' becomes 'SA' (abbreviation).
'army' becomes 'TA' (abbreviation for Territorial Army).
'with' says to put letters next to each other.
'name' becomes 'n' (common abbreviation e.g. on forms).
'sa'+'ta'+'n'='SATAN'
'for' acts as a link.
(Other definitions for satan that I've seen before include "Fiend" , "Prince of Darkness" , "Fallen archangel" , "arch-fiend" , "Old Nick, Lucifer or Beelzebub" .)