New Religion

Why doesn't orthodox Christianity support Mormonism? Is it because they proclaim a new revelation from God? I remember visiting the home of a friend whose father was president of the stake in Syracuse. He made the comparison that just as the New Testament, which led to Christianity, is to the Old Testament, so Mormonism is to the NT. But essentially, orthodox Christians don't agree with Mormons on issues of salvation, revelation, scripture, who the person of Jesus Christ is and other things. Now I ask you, what is the difference between Mormonism and the Episcopal Church USA? Like Mormonism, ECUSA has all the trappings of Christianity. Frank Griswold believes in a new revelation that supercedes scripture. John Spong doesn't believe that Jesus really died for our sins. Charles Bennison believes that "we wrote the scriptures once, we can write them again." I think the Episcopal Church has essentially become an offshoot of Christianity -- a new religion.