I have gotten this question or one very similar a number of times. I am copying and pasting a previous question and answer. After that I will respond further to you question.
Why did Constantine and the Council of Nicaea choose to"edit" The Bible by inserting and removing certain books? What was the real aim of canonization?
This is an easy one! Constantine did not "edit" or change the New Testament in any way. Neither did the Council at Nicaea change the New Testament in any way whatsoever. This is a false rumor which has been supported by a number of people. Most famous of these is Dan Brown in his book The DaVinci Code. From a scholarly point of view the idea that the Council of Nicaea changed the New Testament is sheer nonsense. We have dozens of manuscripts in Greek of the New Testament from the second and third century–generations before Constantine was even born! If Constantine changed the New Testament or if he excised whole portions, surely there would be some evidence in these earlier manuscripts. We have more than one complete Greek New Testament manuscripts (Codex Vaticanus, Sanaiticus and Alexandrinus) from about AD 350, which is about the time the Council of Nicaea took place. There are dozens of manuscripts from the third and even second centuries (Chester Beaty Papurus, Washington Manuscript, Rylands Papyrus, etc.) Again, there is not a shred of evidence that anything was either added to or taken from the New Testament by the Council of Nicaea. In fact, if these bishops had tried to change the New Testament, you can be assured that this move would not have been accepted by the church as a whole, for which the canon of the New Testament had already been fixed for well over one hundred years before the council was held. Add to this the fact that we have tens of thousands of quotes from the New Testament from the early church fathers. If there were some hidden or removed section of the New Testament, there would be some evidence of this fact from the innumerable quotes we have from the early Christian writers. Again, such evidence is completely lacking.
Rest assured that these claims that the New Testament was changed by Constantine is absolutely, without a doubt, false. It is my personal belief that Satan, who is known as the Father of Lies in the New Testament, is the one behind these spurious attacks and unfounded attempts to undermine the authority of the inspired Word of God.
As to canonization, I have a quite a bit of material on this in my book "Reasons for Belief" which is available at www.ipibooks.com. Those who "canonized" the New Testament did not necessarily think of themselves as doing so. Bottom line, the books which were eventually accepted as part of the "canon" (meaning rule) of the New Testament were those which the early church, by consensus, believed to have apostolic authority. In other words, the books which were accepted were those which the church believed the apostles themselves considered to be inspired by God.
OK, now back to your question. The idea that the the bishops at the Council of Nicea added or removed books or entire sections of books is a kind of "urban legend." Not only is there no evidence for this, the evidence we do have (manuscripts of the New Testament, quotes from the Church Fathers) makes this idea completely untenable. Is it possible that a group changed one word here or there? Yes, but in this case, such a change would only show up in some of the manuscripts, making the change obvious. Besides, we have eye witness accounts of what happened at the Council of Nicea. The contents of the New Testament were not even at issue in this meeting. It was about what to do with the Arian heresy.
About the Bible being written my men (and perhaps women), it is obvious that human beings wrote the Bible. No one has ever claimed that the pages of the Bible fell down from the sky. God used human instruments to reveal his will. We have the assurance in 2 Peter 1:19-21 that the writers of the Bible were inspired by God. The way Peter puts it, they were "carried along by the Holy Spirit." Of course, some do not believe the original scriptures are inspired. The massive volume of evidence for the inspiration (prophecy, historical accuracy, etc….) is the main subject of the material at our web site. So the question of the inspiration of the original writings is one matter. Claims that the original scriptures were tampered with later is another matter. The evidence for this is very weak. Evidence for changes as late as the time of Constantine which affects the Bible we have now is completely absent.
John Oakes, PhD