Jesus instructed the young man stating that: 'He was to join none of them, for they were all wrong, that all their creeds were an abomination in his sight; that those professors were all corrupt, that: "they draw near to me with their lips, but their hearts were all far from me, they teach for doctrines the commandments of men, having a form of godliness, but they deny the power there of." ' (JSH 1:19)
This is according to Joseph Smith's vision, for he saw God the Celestial Father and Jesus Christ our Lord, that is our Lord Jehovah/Jesus standing upon the right hand of his and our LORD God Elohim, our Heavenly Father of Spirits, as stated and given multiple times in the New and Old Testament Records (Psalm 110). Stephen of the Seventy, had a like vision of God the Father and Jesus Christ His Son as recorded in Acts chapter 7.
Stephen by the present power of the Holy Ghost was able to see God the Father and His Son Jesus Christ as did also Joseph Smith. As members of The Church of Jesus Christ of Latter-day Saints, we have this visionary understanding of God the Father, Our Father Who Art in Heaven, and Jesus Christ, who is the same as Jehovah; that they are two separate and distinct glorified beings now both in Heaven, Jesus upon the right hand of the Father. (See Psalms 110:1 (1-7) King David by the spirit of the Holy Ghost, knew and understood that his Lord, Jehovah, had a LORD above him. Jesus in the New Testament references this Old Testament scripture (Mark 12:36, Luke 20:42) and it is also referenced elsewhere in the New Testament (Acts 2:34, Hebrews 1:13). (See also: Matthew 26:64, Mark 14:62, Mark 16:19, Luke 22:69, Acts 2:33, Acts 7:55-56, Romans 8:34, Colossians 3:1, Hebrews 1:3, Hebrews 8:1, Hebrews 10:12, 12:2, 1 Peter 3:22, Revelation 5:7, Moroni 7:27, Moroni 9:26, D&C 20:24, D&C 66:12, D&C 76:20 & 23, & John 17:3-5)
'Mormon' is only our nick-name, as we are called for our belief in the record of the Book of Mormon primarily edited and prepared by the prophet Mormon. The actual name of our church is 'The Church of Jesus Christ of Later-day Saints'. And as much as Stephen and others who have witnessed that Jesus Christ stands or sits at the right hand of God the Father in heaven in the Bible scriptures, then just as much, YES, Mormon's are Christians. So why do many 'Traditional Christian' state that we are not? Traditional Christianity believes in and holds to the 'Nicene Creed' as it has been developed over the hundreds of years. That 'creed' of belief by such evolved interpretations, does not generally agree that God the Father and Jesus Christ His Son are two totally separate and distinct beings. Since members of The Church of Jesus Christ of Latter-day Saints cannot accept that conclusion of the Nicene Creed, Traditional Christians state that 'Mormons are not Christians'.
Certainly the Traditional Christianity of the Trinity has written 'history', they being the 'winners' over all they have persecuted over the ages. But still it does seem but ludicrous that they demand to deny Christianity to any who do not conform to their conception of the nature of God when in conclusion they but state that, "We see a distinction in the persons of God, but hold that there is but one God. It is a mystery how this is possible, but understanding God is beyond our ability, and we should not see to have it make sense to us." (Lewis Burkhof, Systematic Theology, pp 89-90) & "The undivided essence of God belongs equally to each of the three persons. The Church confesses the Trinity to be a mystery beyond the comprehension of man." (Lewis Berkhof, Systematic Theology, pp. 87-89) So what they say is a mystery to them, that they do not understand it, and that it is beyond the comprehension of man, YET they will deny anyone who does not believe it—that is 'The Trinity' as they define it, without themselves understanding and comprehending it—to be Christian?
We believe that Jesus Christ of the New Testament and Jehovah, the God of the Old Testament, are one and the same being and our God. And we believe as Paul states in Colossians 2:9, that 'in Jesus dwelleth all the fulness of the Godhead bodily.' Not that God the Father, Who Art in Heaven, and the Holy Ghost are the same being as Jesus Christ/Jehovah, but that Jesus Christ/Jehovah by divine investiture has been empowered to stand and act for and in behalf of the Father in all things, and he is also empowered when the need does arise, to also act for and in the stead of the Holy Ghost; NOT that he is the Holy Ghost, but that the Spirit of Christ can act in the stead and in the same manner as the Holy Ghost when called upon to do so. Being able to act in the fulness of the power of, IS NOT the same as being the same entity or being of whom you are acting in behalf of. A Vice President may well be called upon to act in the fulness of the power of the President when it is necessary that he do so. But certainly he is not the same person or being as is the President.
Misunderstanding this concept of the fulness of the powers to act for each member of the Godhead, which Christ has been empowered to do, may well be what has led to the mixing of God the Father, God the Son/Jesus Christ/Jehovah, and the Holy Ghost to become confused by such as who still are unable to explain away the entire 'mystery' of the Godhead, and who do not fully even today comprehend and understand just what it is.
Final Note: Jesus was crucified based on the charge that he was the Son of God. The Jews who believed correctly in One God, could not understand that God would have a Son who was also God. They did not accept that Jesus was the same person/being as Jehovah of the Old Testament, the One True God of Israel. In the preexistence, Jehovah, the Firstborn son in the Spirit of God the Father of Spirits, was anointed to be the One True God of this Temporal Creation. And under the direction and the command of God the Father of Spirits, as Bishop Eusebius presents it in his Ecclesiastical History, Jehovah, even Jesus Christ, as a God of Spirit, did create the temporal Heavens and Earth. For only those who would pertain unto it, that is be a participating part of it, does so directly minister unto it (D&C 130:5). This is why THE CELESTIAL FATHER, selected and anointed His Firstborn Son in the Spirit, Jehovah, to so stand as the One True God, the Creator, Jehovah the God of the Old Testament, and Jesus Christ the Saviour of what he had created as the Redeemer— he Jehovah/Jesus our One True Ministering God, set by the hand of his Father to be the one and only way to heaven; he also being and acting as Mediator, Advocate, and Intercessor between man and his and our Celestial Father. Yes, in the sense of Christ/Jehovah being the One True God of this temporal world, we do concur, the fulness of the Godhead being bodily invested in him as the one and only way to God. That the doctrine of the Father as God our Celestial Father and that of the Holy Ghost, being also two separate beings who Jesus/Jehovah is empowered to act in the stead thereof as occasion arises, DOES NOT mean that Jesus/Jehovah is all three in one and that the other two are not entities in and of themselves, which they are (D&C 130:22-23).