Belief in deity is welcomed by those people (6)
I believe the answer is:
theism
'belief in deity' is the definition.
'theism' can be an answer for 'belief' (theism is a kind of belief). I'm not sure about the 'in deity' bit.
'is welcomed by those people' is the wordplay.
'welcomed by' means one lot of letters goes inside another (letters welcomed inside).
'those people' becomes 'them' (I've seen this before).
'is' placed inside 'them' is 'THEISM'.
Can you help me to learn more?
(Other definitions for theism that I've seen before include "Belief in a deity" , "The doctrine or belief in the existence of a God or gods" , "Belief in a creator" , "of faith" , "Belief in existence of a God revealed to man" .)