Religion is embraced by them (6)
I believe the answer is:
theism
'religion' is the definition.
(I know that theism is a type of religion)
'is embraced by them' is the wordplay.
'embraced by' is an insertion indicator.
'is' put within 'them' is 'THEISM'.
(Other definitions for theism that I've seen before include "Belief in a creator" , "Belief in a deity" , "The doctrine or belief in the existence of a God or gods" , "Belief in existence of a God revealed to man" , "of faith" .)