Just because a group uses the name of Jesus and says it affirms and promotes the Jesus of the Bible does not automatically mean it does. The fact is that Mormonism teaches a Jesus that is different from the Scriptures.
"In bearing testimony of Jesus Christ, President Hinckley spoke of those outside the Church who say Latter-day Saints 'do not believe in the traditional Christ.' 'No, I don't. The traditional Christ of whom they speak is not the Christ of whom I speak. For the Christ of whom I speak has been revealed in this the Dispensation of the Fullness of Times. He together with His Father, appeared to the boy Joseph Smith in the year 1820, and when Joseph left the grove that day, he knew more of the nature of God than all the learned ministers of the gospel of the ages.'" (LDS Church News Week ending June 20, 1998, p. 7).
The late president of the Mormon church, Gordon B. Hinckley, clearly stated that what the Mormon church teaches about Jesus and what the Christian church teaches is not the same thing. Why is that? Because it teaches things about Jesus that contradict Scripture.
In Mormonism, God came from another world (Mormon Doctrine by LDS Apostle Bruce McConkie, p. 321) and has a goddess wife (LDS Articles of Faith, by James Talmage, p. 443; 516). It is from these physical parents (who are gods) that Jesus and the devil were produced through physical relations. Therefore, they are spirit brothers (Mormon Doctrine, p. 163). The source of Jesus and the nature of Jesus both contradict the Bible.
According to the Bible, there is only one God in all existence (Isaiah 43:10; 44:6, 8; 45:5). God is a Trinity, which is the teaching that there is only one God in all existence who eternally exists as three distinct, simultaneous persons: the Father, the Son, and Holy Spirit. They are not three separate gods as Mormonism teaches (James Talmage, Articles of Faith, p. 35). Because they have God wrong, they have Jesus wrong. The real Jesus is the second person of the Trinity, eternal in nature, and not the brother of the devil. Jesus is not the literal offspring of a god and his goddess wife who came from another world.
Therefore, although Mormonism claims to teach the Jesus of the Bible, in reality, it does not. This is why it is not really Christian.