Killing makes church service some land (8)
I believe the answer is:
massacre
'killing' is the definition.
(I know that massacre is a type of murder)
'church service some land' is the wordplay.
'church service' becomes 'mass' (Mass is a type of church service).
'some land' becomes 'acre' (unit of land).
'mass'+'acre'='MASSACRE'
'makes' is the link.
(Other definitions for massacre that I've seen before include "Brutal slaughter" , "Slaughter, holocaust" , "Heavily defeat" , "Butchery" , "Inflict a heavy defeat" .)