A creed contains nothing like it! (4,3)
I believe the answer is:
'it' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'a creed contains nothing' is the wordplay.
'a creed' becomes 'nicene' (Nicene Creed is an example).
'contains' is an insertion indicator.
'nothing' becomes 'O' (O resembles 0).
'nicene' going around 'o' is 'NICE ONE'.
'like' is the link.
Can you help me to learn more?
(Other definitions for nice one that I've seen before include "very good" , "like it!" , "Congratulatory phrase" .)