Start using some rejected religious text (5)
I believe the answer is:
sutra
'religious text' is the definition.
'sutra' can be an answer for 'text' (I have seen 'sacred text' mean 'sutra' so perhaps 'text' could also mean 'sutra'). I am not certain of the 'religious' bit.
'start using some rejected' is the wordplay.
'some' indicates the answer is hidden within the clue.
'rejected' says the letters should be written in reverse.
'artus' is hidden in the letters of 'start using'.
'artus' backwards is 'SUTRA'.
Can you help me to learn more?
(Other definitions for sutra that I've seen before include "A Buddhist scripture" , "Buddhist literature" , "Book of aphorisms" , "Ornamental arm band" , "Sanskrit aphorisms" .)