Health worker, one who believes criticism must be accepted (9)
I believe the answer is:
therapist
'health worker' is the definition.
(I know that therapist is a type of allied health professional)
'one who believes criticism must be accepted' is the wordplay.
'one who believes' becomes 'theist' (someone who believes in a god).
'criticism' becomes 'rap' (as in taking the rap for a mistake).
'must be accepted' is an insertion indicator.
'theist' going around 'rap' is 'THERAPIST'.
(Other definitions for therapist that I've seen before include "provider of treatment" , "nurse" , "Help" , "Medical practitioner" , "Healer of disease" .)