Most Christians believe that Jesus Christ was "truly God and truly man, in whom the divine and human natures are perfectly and inseparably united." He is the only begotten Son of the Father, born of the Virgin Mary by the power of the Holy Spirit.
Mormons believe that Jesus is the Son of God in the most literal sense. He is eldest brother of all mortals and firstborn spirit child of God. He was Jehovah of the Old Testament but became Jesus Christ of the New Testament when he was born into mortality. They believe that from Mary, a mortal woman, he inherited the capacity to die, and from God, an exalted being, he inherited the capacity to live forever.