Veilid,
"Belonging to the community" and just having friends are two different things. I understand "Belonging to the community" as actually participaiting in its life somehow: for example, in my case, help to edit local Russian newspaper. I did have, and still do, some Russian friends (not too close friends, I do not know the proper English word for it). But there are very few.
Why underastanding may not be good enough... Well, I give you an example. For instance, a woman who is seeking help after raped may understand that male therapists are knowlegeble, but feels more comfortable with a female one. Same thing is possible with cultural issues: understanding that one is a good professional, but not developing enough comfort. It is of course client's issue, not therapist's.