Religious education brings in very little money, or 'ready' (4)
I believe the answer is:
ripe
'ready' is the definition.
(similar in meaning)
'religious education brings in very little money' is the wordplay.
'religious education' becomes 'RE' (abbreviation).
'brings in' indicates putting letters inside.
'very little money' becomes 'ip' (I can't justify this - if you can you should give a lot more credence to this answer).
're' going around 'ip' is 'RIPE'.
'or' is the link.
Can you help me to learn more?
(Other definitions for ripe that I've seen before include "Mature and ready to be eaten" , "daring" , "Seasoned, fully grown" , "Mature, ready for eating" , "Fully developed or matured" .)