Can I really call some one my brother if they teach another salvation? If they find salvation in the cup are they my Christian twin. If they believe the bread is salvific is there a true spiritual kinship then is thier salvation the same as mine. Is it not grace alone, Christ alone, faith alone?

I am amazed that you are so quickly deserting Him who called you by the grace of
Christ, for a different gospel; which is really not another; only there are some
who are disturbing you and want to distort the gospel of Christ. But even if we,
or an angel from heaven, should preach to you a gospel contrary to what we have
preached to you, he is to be accursed! As we have said before, so I say again
now, if any man is preaching to you a gospel contrary to what you received, he
is to be accursed! - Gal 1:6-9