In church a lovely saintly ring (4)
I believe the answer is:
halo
'saintly ring' is the definition.
(I've seen this before)
'in church a lovely' is the wordplay.
'in' indicates the answer is hidden within the clue.
'HALO' is hidden in the letters of 'church a lovely'.
(Other definitions for halo that I've seen before include "Ring round head of saint" , "Ring of light round head" , "Aura round admired person" , "Corona" , "Ring of light (signifying holiness)" .)