Is LDS theology based in part on old heresies?
The LDS teaching that Jesus was not always part of the Godhead and that Jesus acheived God status and became a God is essentially the fourth century heresy of Arianism. However, J. Reuben Clark, Jr. and B.H. Roberts were among the first to attempt to show that LDS doctrine was not Arianism.
The followers of Arius believed that Christ was not always God. Christ was a creature of God the Father just like we are creatures of God. Jesus was the most perfect of all creatures. God is one, and next to God, as close as possible and yet outside of Him, the reflection of His power, is the most perfect of all created beings, the Word, the Logos of St. John, who could pass for God and be like Him but in itself the Word was not God because He had been born and therefore a time existed when He did not exist. All of this should sound VERY familiar to those schooled in LDS theology.
Joseph Fielding Smith actually supported Arius in his Answers to Gospel Questions, Vol. 3, p.167 where he states, "In the fact that the creed declares that in the Trinity, 'None is greater or less than Another, but the whole Three Persons are Co-Eternal together, and Co-Equal' we find a conflict which is contrary to what is written in the scriptures. Arius, at that council, tried to establish one truth that was rejected. That is, that there never was a Son that was not younger than his Father, but the creed emphatically declares that the Son, as well as the Father, is 'Uncreate.'
Arius did not refuse to refer to Jesus Christ as God or to ascribe to Him divine perfections. His point, like that of the LDS, was that Jesus was not always God; Jesus like us was a creature of God. LDS doctrine attempts to distance itself from Arianism by contending that Christ always existing from before creation as an intelligence, just like the rest of us, thus ignoring that God the Father created spirit bodies for our intelligences, including that of Jesus.
I believe that LDS apologists try so hard to distance themselves from Arius rather than embrace him as one of the last faithful during the "Great Apostasy" because most of the Christian world formally rejects Arianism as denying the divinity of Jesus. Arius did not deny the divinity of Jesus, but he, like his LDS counterparts, did not tie the divinity of Jesus to a definition that required His always being God.
Other heresies:
I have found parallels in LDS thought to some of the other great Heresies of Christianity. Take the Gnostic belief in having received "secret knowledge" and of receiving new scripture through revelations, that we are immortal beings from the beginning. Or the Montanist belief in revelations being given to a man from Cybele, named Montanus and two woman prophets (as in New Testament times) named Maximilia and Priscilla. To them was revealed what Joseph Smith also claimed to receive and that was that they were living in the last days and announced the return of Jesus. They also told of the coming of the new Jerusalem which would lie between Tymion and Pepuza, Phrygian towns. And the heresy of the Cathari, the pure.
All heresies appear to have this in common, they make the new followers of the heresy the pure ones, those chosen of God. D&C 101:17-18, "Zion shall not be moved out of her place, notwithstanding her children are scattered. They that remain, and are pure in heart, shall return, and come to their inheritances, they and their children, with songs of everlasting joy, to build up the waste places of Zion-" (Note the reference to the "pure". Also note that this scripture is yet to be fulfilled since the LDS were driven from Zion, never to return or build up its waste places in Jackson County.) Also see D&C 38:8, 50:29, 76:116, 88:74.
In his chapter on Catharism from his book, Great Heresies & Church Councils, p. 123, Jean Guitton says some interesting things about secrecy and prophets in the early church,
"Christianity was born in secrecy; it is a victorious conspiracy. The party of Jesus was virtually a conspiracy within Judaism. When this party was immersed within the pagan masses, its methods did not change: the mystic supper, taken in the home for fear of the Jews, had been inaugurated on the first Easter eve.
"There have always been in the body of the Church 'parties of the pure' about to rise or to take on new
shapes.
"The Apostles were the successors of the prophets; they were prophets invested with supreme authority. The moment of Jesus and those He sent was the divine moment of prophetism--the moment when Purity was the power that subdued all. The remarkable thing about the movement that started from Jesus is that this moment of purity gave rise to an Institution. The apostolate was succeeded, not by another prophetism but by the Church: the reign of continuity, succession, and normative institution to which the prophets are subject even more than they were to the Jewish priesthood. Prophets still existed. They came and disappeared without a break. In the time of the Church the 'prophetic office' never ceased. But prophets rose up and acted within the Church. Their dealings were with the Church. Some were controlled and absorbed by the Church; others were rejected because their purity grew anarchic and threatened the institution.
"The Church never was a 'party of the pure'. She sought to achieve not so much perfect purity as purification. Instead, she set up secondary institutions through which lost purity could be recovered: the offices of forgiveness, penitence, and gradual education".