On titles this article on the swastika talks about Bishop Sheen this one refers to Mother Teresa and this one refers to Sister Ruth Before entering the religious life as a Dominican nun Sister Ruth was a litigator with Manhattan law firm This one makes a number of references to Rabbi Kushner So apparently it is quite common to use the religious respectful title for at least Christian and Jewish leaders I don t know the first thing about Sheiks and Imams and such though Also if you are just calling someone a rabbi or a Catholic priest for example you do not capitalize it