Your opinion. One could as easily say that you are not a Christian if you are not a Catholic.
Is it Christian to be small-minded?
For the record, I am not a mormon; I don’t subscribe to any denomination because denominations are a contrivance of men and each denomination subscribes to their interpretation of the meaning of God’s word. As long as your belief system does not impinge on other people’s right to life, liberty and the pursuit of happiness (and islam does advocate that line of evil) you are free to practice as you please and to believe that a mormon is not a Christian. I have the equal right to say that you are being small-minded.
Thankfully, the Constitution allows all of us to believe and practice as we see fit, or to not believe in God at all.
No, the Constitution prevents Congress from establishing an official Church of the United States.