Not a professor of divinity, evidently (7)
I believe the answer is:
atheist
'professor of divinity evidently' is the definition.
I can't tell whether this definition defines the answer.
'not a' is the wordplay.
I cannot quite understand how this works, but
'a' is within the answer.
The remaining letters 'theist' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for atheist that I've seen before include "One denying existence of a god" , "One who disbelieves the existence of gods" , "Person who does not believe in existence of a god" , "Unbeliever" , "One doesn't believe" .)