Outside the pages of the New Testament itself, Athanasius is probably the man to whom we chiefly owe the preservation of the Christian faith. He was born around AD 298, and lived in Alexandria, Egypt, the chief center of learning of the Roman Empire.
In 313 the Emperor Constantine issued the Edict of Milan, which changed Christianity from a persecuted to an officially favored religion. About six years later, a presbyter (elder, priest) Arius of Alexandria began to teach concerning the Word of God (John 1:1) that "God begat him, and before he was begotten, he did not exist." Athanasius was at that time a newly ordained deacon, secretary to Bishop Alexander of Alexandria, and a member of his household. His reply to Arius was that the begetting, or uttering, of the Word by the Father is an eternal relation between Them, and not a temporal event. Arius was condemned by the bishops of Egypt (with the exceptions of Secundus of Ptolemais and Theonas of Marmorica), and went to Nicomedia, from which he wrote letters to bishops throughout the world, stating his position.
The Emperor Constantine undertook to resolve the dispute by calling a council of bishops from all over the Christian world. This council met in Nicea, just across the straits from what is now Istanbul, in the year 325, and consisted of 317 bishops. Athanasius accompanied his bishop to the council, and became recognized as a chief spokesman for the view that the Son was fully God, co-equal and co-eternal with the Father.
The party of Athanasius was overwhelmingly in the majority. (The western, or Latin, half of the Empire was very sparsely represented, but it was solidly Athanasian, so that if its bishops had attended in force, the vote would have been still more lopsided.) It remained to formulate a creedal statement to express the consensus. The initial effort was to find a formula from Holy Scripture that would express the full deity of the Son, equally with the Father. However, the Arians cheerfully agreed to all such formulations, having interpreted them already to fit their own views. (Those of you who have conversed with members of the Watchtower Society, who consider themselves the spiritual heirs of Arius, will know how this works.) Finally, the Greek word "homo-ousios" (meaning "of the same substance, or nature, or essence") was introduced, chiefly because it was one word that could not be understood to mean what the Arians meant. Some of the bishops present, although in complete disagreement with Arius, were reluctant to use a term not found in the Scriptures, but eventually saw that the alternative was a creed that both sides would sign, each understanding it in its own way, and that the Church could not afford to leave the question of whether the Son is truly God (the Arians said "a god") undecided. So the result was that the Council adopted a creed which is a shorter version of what we now call the Nicene Creed, declaring the Son to be "of one substance with the Father." At the end, there were only two holdouts, the aforesaid Secundus and Theonas.
(For a dramatic but historically accurate account of the Council of Nicea, see the play, The Emperor Constantine, by Dorothy L Sayers, available in book form.)
No sooner was the council over than its consensus began to fall apart. Constantine had expected that the result would be unity, but found that the Arians would not accept the decision, and that many of the orthodox bishops were prepared to look for a wording a little softer than that of Nicea, something that sounded orthodox, but that the Arians would accept. All sorts of compromise formulas were worked out, with all shades of variation from the formula of Nicea.
In 328, Alexander died, and Athanasius succeeded him as bishop of Alexandria. He refused to participate in these negotiations, suspecting (correctly as it turned out) that once the orthodox party showed a willingness to make reaching an agreement their highest priority, they would end up giving away the store. He defended the full deity of Christ against emperors, magistrates, bishops, and theologians. For this, he was regarded as a trouble-maker by Constantine and his successors, and was banished from Alexandria a total of five times by various emperors. (Hence the expression "Athanasius contra mundum," or, "Athanasius against the world.") Eventually, Christians who believed in the Deity of Christ came to see that once they were prepared to abandon the Nicene formulation, they were on a slippery slope that led to regarding the Logos as simply a high-ranking angel. The more they experimented with other formulations, the clearer it became that only the Nicene formulation would preserve the Christian faith in any meaningful sense, and so they re-affirmed the Nicene Creed at the Council of Constantinople in 381, a final triumph that Athanasius did not live to see.
It was a final triumph as far as councils of bishops were concerned, but the situation was complicated by the fact that after Constantine there were several Arian emperors (not counting the Emperor Julian, who was a pagan, but correctly saw that the most effective way to fight Christianity was to throw all his weight on the side of the Arians). Under one of them Arian missionaries were sent to convert the Goths, who became the backbone of the Roman Army (then composed chiefly of foreign mercenaries) with the result that for many years Arianism was considered the mark of a good Army man. The conversion of Clovis, King of the Franks, in 496, to orthodox Christianity either gave the Athanasian party the military power to crush Arianism or denied the Arian Goths the military supremacy that would have enabled them to crush Athanasian Christianity, depending on your point of view.
Since Alexandria had the best astronomers, it was the duty of the Bishop of Alexandria to write to the other bishops every year and tell them the correct date for Easter. Naturally, his annual letter on this topic contained other material as well. One Easter Letter (or Paschal Letter) of Athanasius is well known for giving a list of the books that ought to be considered part of the canonical Scriptures, with a supplementary list of books suitable for devotional reading.
For the New Testament, he lists the 27 books that are recognized today. (If you will look at your list of New Testament books, you may note that Matthew through 2 Thessalonians were never in dispute, that the next four were subject to relatively little dispute, and that the remaining books had more trouble being accepted. There were also a few books that looked as if they might make the list, but eventually did not, the most conspicuous being the Epistle of Barnabas, the Epistle of Clement, and the Shepherd of Hermas.)
For the Old Testament, his list is like that used by most Protestants, except that he omits Esther, and includes Baruch, with the letter of Jeremiah. His supplementary list is Wisdom, Sirach, Tobias, Judith, and Esther. He does not mention Maccabees.
Two quotations from the writings of Athanasius follow:
We were made "in the likeness of God." But in course of time that image has become obscured, like a face on a very old portrait, dimmed with dust and dirt.
When a portrait is spoiled, the only way to renew it is for the subject to come back to the studio and sit for the artist all over again. That is why Christ came--to make it possible for the divine image in man to be recreated. We were made in God's likeness; we are remade in the likeness of his Son.
To bring about this re-creation, Christ still comes to men and lives among them. In a special way he comes to his Church, his "body", to show us what the "image of God" is really like.
What a responsibility the Church has, to be Christ's "body," showing him to those who are unwilling or unable to see him in providence, or in creation! Through the Word of God lived out in the Body of Christ they can come to the Father, and themselves be made again "in the likeness of God."
[ Editor's Note: the biography just breaks off here. I'm working on getting the rest of it and patching this up. Sorry 'bout that . . .]