@MeanMrMustard: because what you state is the view of Jesus according to Mormons (or Islam). So Christianity is a form of Judaism where the Messiah has returned (if you want to take a true historic viewpoint).
You cannot agree to reject the divinity of Christ as elaborated in the Nicene Creed and still be a Christian, it’s kind of the definition of being a Christian, every denomination has held this since the establishment of Christianity. The trinity is just the mechanics of how God came to Earth and died for our sins in a human body, because nobody can ‘see’ God in completeness and live, therefore there must be a part of God that came down (the Son) and a connecting force (the Holy Spirit). It’s more of an explanation, but you cannot say they are separate, that would be considered heresy. You can call your belief something else, but the majority of Christians would agree you are not a Christian if you reject that.
Judaism had similar expectations according to Rabbi Johanan bar Nappaha and Rabbi Abba Bar Kahana (3rd century AD) the Jews were still expecting God-in-the-flesh. The Chabad believes Rabbi Mendel Schneerson to be similarly the Messiah, a God-on-earth. I think more modern Judaism may reject that notion, but that may be to distinguish it from the idea of Jesus.
Note that even the Quran teaches that Jesus was the Messiah and will return during their interpretation of Armageddon, however like Mormons and Millerites do not teach that he is (a) God.