Robbery by some atheists (5)
I believe the answer is:
heist
'robbery' is the definition.
(heist is a kind of robbery)
'some atheists' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'HEIST' can be found hidden inside 'atheists'.
'by' is the link.
(Other definitions for heist that I've seen before include "bank job in America?" , "Mugging" , "Armed hold-up (sl.)" , "crime?" , "Armed robbery" .)