Faith in Jedi, a habit brought up (5)
I believe the answer is:
bahai
'faith' is the definition.
(I know that Bahai is a faith)
'in jedi a habit brought up' is the wordplay.
'in' indicates a hidden word.
'brought up' is a reversal indicator (in a down clue, letters go up).
'iahab' is hidden in the letters of 'jedi a habit'.
'iahab' backwards is 'BAHAI'.
(Other definitions for bahai that I've seen before include "Religion seeking world peace" , "Religion founded in the 19th-century" , "Religion of peace/unity" , "Religious follower" , "Religion emphasising unity and peace" .)