Don’t forget that Mormonism also teaches that Lucifer (Satan) is Jesus’ half-brother. I asked a Mormon I worked with that question point blank and he said, yes, it’s true.
According to Mormonism, Jesus is the offspring of God from a sexual relationship He had with Mary (there goes the virgin birth), and Lucifer, who became the devil, is the offspring of God from a sexual relationship with another of God’s many spirit wives.
No, Mormonism is not Christian as they do not worship or follow the Jesus of the Bible. They follow a different Jesus.
But I fear, lest by any means, as the serpent beguiled Eve through his subtilty, so your minds should be corrupted from the simplicity that is in Christ. For if he that cometh preacheth another Jesus, whom we have not preached, or if ye receive another spirit, which ye have not received, or another gospel, which ye have not accepted, ye might well bear with him. (2 Corinthians 11:3-4)
Thus you can tell Mormon missionaries thatt hey are in the Bible:
For such are false apostles, deceitful workers, transforming themselves into the apostles of Christ. (2 Corinthians 11:13)