Johns therapist strives to provide an atmosphere of acceptance and respect no matter what comes up during the sessions. in the context of humanistic approaches to personality, johns therapist is providing what

I believe the answer is: unconditional positive regard

unconditional positive regard refers to a concept of therapy that conducted by accepting and providing support for whatever the patient says or does.
This concept is used to make the patient believe that the therapy is a safe environment for them where they can truly be themselves without facing any judgement.