Article first put together for believer (6)
I believe the answer is:
theist
'believer' is the definition.
(theist is a kind of believer)
'article first put together' is the wordplay.
'article' becomes 'the' (the definite article in English).
'first' becomes 'ist'.
'put together' means one lot of letters go next to another.
'the'+'ist'='THEIST'
'for' is the link.
(Other definitions for theist that I've seen before include "One who believe in a god" , "Believer in a creator god" , "Tithes (anag.)" , "Person who believes in the existence of a god" , "Believer in a god or gods" .)