Treat others as you'd like to be treated is a universal principle. Therapists who avoid working with other faiths and cultures can be assured that there is common ground to work from.
Working with people with different beliefs can be challenging, especially for psychological therapists. By definition, every client holds some beliefs differing from the therapist's but there is something particularly daunting about codified cultural and religious belief systems.
Clients will often seek out therapists of a similar culture or faith, fearing (sometimes correctly) that an ignorant or antagonistic therapist may question basic beliefs which they do not wish to examine.
Therapists may also shy away from clients of different cultures or faiths, fearing that a misunderstanding on their part may upset or offend the client, possibly even to the level of formal complaints. Such a lack of confidence does little for rapport.
Whilst therapists cannot know the details of every faith and culture they might encounter and should think carefully before attempting to work within frameworks they do not understand, there is one principle common to almost all belief systems: the Golden Rule;
do unto others as you would have them do unto you.
Religious Tolerance.org lists 21 world religions (including Christianity, Judaism, Islam, Hinduism & Sikhism) and a number of other philosophical systems which contain a version of the Golden Rule.
The site notes that most religions make some exception for non-believers, but the existence of this almost universal principle should reassure the uncertain that there can be common ground.
A wise therapist would not, of course, presume to believe that there can be complete agreement. The comedian Emo Phillips has illustrated the dangers of pursuing the search for common ground too far.
I was walking across a bridge one day, and I saw a man standing on the edge, about to jump off. So I ran over and said "Stop! don't do it!" "Why shouldn't I?" he said.
I said, "Well, there's so much to live for!" He said, "Like what?"
I said, "Well...are you religious or atheist?" He said, "Religious."
I said, "Me too! Are you christian or buddhist?" He said, "Christian."
I said, "Me too! Are you catholic or protestant?" He said, "Protestant." I said, "Me too! Are you episcopalian or baptist?"
He said, "Baptist!" I said,"Wow! Me too! Are you baptist church of god or baptist church of the lord?" He said, "Baptist church of god!"
I said, "Me too! Are you original baptist church of god, or are you reformed baptist church of god?" He said,"Reformed Baptist church of god!"
I said, "Me too! Are you reformed baptist church of god, reformation of 1879, or reformed baptist church of god, reformation of 1915?" He said, "Reformed baptist church of god, reformation of 1915!"
I said, "Die, heretic scum", and pushed him off.