Sir, I must ask you-what research have you (yes you) done on the First Ecumenical Council, also known as the First Council of Nicea? To be truthful, the "information" you mention iin your post is quite misleading, as well as extremely scant and biased.
Also, your statement that the books "left out" of the Canon of Scripture by the Holy Fathers of the Counicl of Nicea are to be found in the Book of Mormon is MORE than misleading-it is patently false.
The Book of Mormon has absolutely NOTHING to do with either the New Testament, nor the books that were, as you mentioned, "left out." While I am sure that you are totally mystified as to the truth about why these books were left out, you are certainly also mystified by the contents of the Book of Mormon.
The Book of Mormon "appeared" in this world, according to Joseph Smith, founder of Mormonism, as a book inscrobed in an ancioent and unknown language on golden plates. The plates came to Smith, as he told it, as a gift from the angel Moroni, who also quite obligingly translated this unknown language into English for Smith. After the translation was made, the plates unfortunately-or, fortunately-however you may look at it-disappeared.
The Book of Mormon presents an unChristian doctrine, going from science fiction like stories to telling the fate of the Lost tribes of Israel-they settled in the area that was later know as The United States of America. While the Mormons, of cour4se, still believe this fable, there has NEVER been any evidence whatosver to testify to the fact of Lost Tribes of Israel inhabiting North America.
The books "left out" of the Canon of Scripture by the Holy Fathers of the First Council of Nicea were a mish mosh of so-called "Gospels," that claimed to be authored by different persons known to us from the Life of Christ, and included apocryphal stories concering the life of Jesus as a child, and later, even going so far as to claim a "marriage" between Jesus and Saint Mary Magdelene. Several of these false "Gospels" also were heavy on Gnostic doctrines, which had more in common with the paganism of Rome and Greece than with Christianity.
The Book of Mormon is even more of a fairy tale than these so-called "Gospels." However, IT DOES NOT concern itself with Gnostic doctrines, not any of the other materials from these books that were "left out." And, of course, the books that were "left out" have absolutely nothing at all to do with Lost Tribes of Israel inhabiting North America! In short, the books "left out" as you refer to it, have absolutely NOTHING whatsoever to do with the Book of Mormon-NOTHING, in any way, shape, or form!
It would behoove you, sir, to look into the First Council of Nicea from a historical viewpoint, and find out what truly happened there (a good place to start would be the "Nicene and Post Nicene Fathers, Series II, at
www.ccel.org/fathers2/NPNF2-14/TOC.htm), rather than simply contiunue to repeat the nonsense from some tract that seemingly includes no knowledge about the First Council of Nicea!
Also, Christianity was not "founded" at the First Council of Nicea, but on the First Pentecost in 33 A.D., when the APostles and disciples of Christ gathered together to institute the Church of Christ.