Different Jesus, different gospel.
Since you say the church doesn't teach what I claim it does, here's a more detailed summary. If you wish to read further into the issue, check this LDS publication out:
churchofjesuschrist.org/bc/c…
The LDS godhead consists of three persons: Our Father in Heaven, Jesus Christ, and the Holy Ghost. The first two have bodies of flesh and bone, while the third is a spirit. In all of creation, this godhead is repeated, so there are many Heavenly Fathers and Jesus’ out there.
- “Heavenly Father, Jesus Christ, and the Holy Ghost are called the Godhead. They are unified in purpose. Each has an important assignment in the plan of salvation. Our Heavenly Father is our Father and ruler. Jesus Christ is our Savior. The Holy Ghost is the revealer and testifier of all truth.” (Gospel Principles (GP), Ch. 7)
- “(They) are three separate persons. (Gospel Fundamentals (GF), pg. 28)
- “(The Holy Ghost) does not have a body of flesh and bones as our Father in Heaven and Jesus have. He is a spirit. He looks like a man.” (GF, pg. 28)
Heavenly Father, a physical god, aka Elohim; a man who achieved godhood on another planet; the one we should worship; maker of Adam and Eve:
- “How many Gods there are, I do not know. But there never was a time when there were not Gods and worlds, and when men were not passing through the same ordeals that we are now passing through. That course has been from all eternity, and it is and will be to all eternity. You cannot comprehend this; but when you can, it will be to you a matter of great consolation.” (Brigham Young, October 8, 1859, Journal of Discourses 7:333).
- “It will help us to remember that our Father in Heaven was once a man who lived on an earth, the same as we do. He became our Father in Heaven by overcoming problems, just as we have to do on this earth.” (GF, pg. 204)
- "Joseph Smith taught: “It is the first principle of the Gospel to know for a certainty the Character of God. … He was once a man like us; … God himself, the Father of us all, dwelt on an earth, the same as Jesus Christ himself did.” (GP, Ch. 47)
- “Our Father in Heaven is the only being we should worship.” (GF, pg. 3)
- “God is the Supreme and Absolute Being in whom we believe and whom we worship.” (GF, ch. 1)
- “Prayer is a sincere, heartfelt talk with our Heavenly Father. We should pray to God and to no one else. We do not pray to any other being or to anything made by man or God.” (GP, Ch. 8)
- “He had His Son, Jesus, make the sky and the earth.” (GF, pg. 3)
- “Jesus made the earth under our Father in Heaven’s direction. (GF, pg. 20)
- “Our Father in Heaven then made a man and a woman.” (GF, pg. 19)
Jesus, a physical god; aka Jehovah, the god of the Old Testament; the literal son of Heavenly Father; the one we should obey; the maker of earth.
- “Every person who lives on this earth was our brother or sister in heaven. The oldest child in our heavenly family was Jesus Christ. He is our oldest brother.” (GF, pg. 5)
- “Jesus made the earth. … When Jesus had done all this, the earth was ready for people to live on it. (GF, pg. 19)
- “Jesus Christ was the God of the Old Testament, and it was He who conversed with Abraham and Moses. It was He who inspired Isaiah and Jeremiah; it was He who foretold through those chosen men the happenings of the future, even to the latest day and hour. (Spencer W. Kimball, In Conference Report, Apr. 1977, 113; or Ensign, May 1977, 76.)
- “Our Father in Heaven wants us to follow and obey Jesus.” (GF, pg. 12)
The Holy Ghost is a spirit, in the form of a man; he works with the Heavenly Father and Jesus.
- “He is a spirit. He looks like a man.” (GF, pg. 28)
- “Our Father in Heaven loves each of us. He sends the Holy Ghost to guide us and teach us the truth. However, the Holy Ghost will help us only if we try earnestly to follow the commandments and instructions He brings us from our Father in Heaven and Jesus.” (GF, pg. 30)
- “The Holy Ghost tells each of us what Jesus wants us to do, and to receive eternal life we must spend the rest of our lives obeying and serving Him.” (GF, pg. 204)
It also promises that a man can similarly achieve godhood if he follows their rules:
- “To live in the highest part of the celestial kingdom is called exaltation or eternal life. … They will receive everything our Father in Heaven has and will become like Him. They will even be able to have spirit children and make new worlds for them to live on, and do all the things our Father in Heaven has done.” (GF, pg. 201)
- "Those who receive exaltation in the celestial kingdom through faith in Jesus Christ will receive special blessings. The Lord has promised, “All things are theirs.” These are some of the blessings given to exalted people:
They will live eternally in the presence of Heavenly Father and Jesus Christ.
They will become gods.
They will be united eternally with their righteous family members and will be able to have eternal increase." (GP, Ch. 47)
So, Mormonism teaches that there are many such gods working in the same way as the being they call Heavenly Father, thus meeting the requirements to be classified as a polytheistic faith.
This, of course, directly contradicts the Biblical view of God, which is succinctly stated in Isaiah 44:
- “This is what the Lord says—Israel’s King and Redeemer, the Lord Almighty: I am the first and I am the last; apart from me there is no God."
The differences between Mormonism and Biblical Christianity are stark: Mormons have a different god, a different 'Jesus' and a different plan of salvation. They are not Christian.