Recently, a U S Court ruled that Shira (Islamic) Law can be used, if appropriate. Based on that ruling Halakhah (Jewish Law) can also be used. More than 2000 years ago Hillel ruled that a half slave must be freed because the half slave could not marry a slave because of being half free and could not marry a free person because of being half slave. By freeing the half slave the newly free person could now marry a free person. Based on those rulings I believe that Gay marriage must be allowed because a gay person could not emotionally marry one of the opposite sex and not marry a same sex partner in most states.