There are a number of materials available to assist any endeavour to determine the form of the earliest N.T. writings.
There are nearly 5000 Greek MSS and thousands of Biblical quotations in the writings of the church fathers; the Greek material falls into four categories:-
1. Papyri. This was used until the early fourth century. Papyrus texts are denoted with a 'P' followed by a designated number; among the most important of these are:-
(a)P52 (Rylands), containing John 18:31-34,37-38, usually dated ca. 130 CE. (b)The Chester Beatty papyri; P45, fragments of the Gospels and Acts, 3rd cent; P46 containing Rom, Heb, 1 and 2 Cor, Eph, Gal, Phil, Col and 1 Thess - in that order, dated early 3rd cent; P47, containing Rev 9-17, dated late 3rd cent. (c)The Bodmer papyri; P66, most of John 1:1-14:26, dated ca. 200 CE; P72 containing Jude, 1 and 2 Peter, dated 3rd or 4th cent; P75, parts of Luke and John, dated early 3rd cent.
2. Parchment (or vellum) MSS were either written in large-capital letter style, where the words were not separated; these are called uncial MSS or majuscules and were used between the fourth and eleventh centuries; miniscules were MSS where the writing was smaller and in a running-hand style and this was used from the ninth century onwards. The earliest extant MSS from this type is from 835 CE. This MSS in this group are enumerated by Arabic numbers and now reach, because of their number, into the 2000's; many of these only contain the Gospels and 90% are Byzantine in text.
From the 3rd cent. only a few fragments of parchment MSS been preserved - one of the most important being 0189 - a leaf with Acts 5:3-21 from the 2nd/3rd cent and 0212 a 3rd cent witness for the Diatessaron. From the 4th cent., there are other MSS of importance.
(B)Vaticanus. Not complete having O.T and incomplete N.T; early 4th cent.
Sinaiticus. O.T nearly complete and complete N.T but includes apocryphal Barnabas and part of Hermas; middle 4th cent.
(A)Alexandrinus. Once a complete Bible, but includes apocryphal 2 Clement; probably 5th cent.
(C)Ephraemi. 5th cent and a palimpest written in the 5th cent but erased in 12th; only 5/8 of NT still present in MS.
(D)Two MSS called Codex Bezae and Claromontanus from 5th/6th cent.
(G)Boernerianus. Ninth cent; rep. Western text of Paul's letters - but omits Heb.
(W)Freer Gospels. 5th cent from Egypt. The text varies.

Uncials are originally denoted by a letter of the alphabet in English, Greek or Hebrew. Now, over 260 uncials are known and because of the number, the system for identifying them is a zero prefixed to a number.
3. Lectionaries. These are service books for liturgical use in church services, containing N.T passages to coincide with the church's year; some 2000 have now been catalogued and there are four times as many with the Gospels as for Acts with the letters combined. They do not contain the whole N.T. They are indicated by a 'l' followed by a number.
4. Quotations by the church fathers. The fathers did not always quote the passages they were using accurately; furthermore it is probable that the MSS containing their writings have also suffered the same problems that other MSS have done in their transmission. Furthermore, they used the 'version' popular in the geographical area in which they wrote. It appears that Tertullian and Cyprian used the Western text whilst Clement of Alexandria primarily used an Egyptian text, and Origen used both Egyptian and Caesarean texts.
Because of the 'families' that exist, groupings have been made for the different text types. The types are usually classified as Syrian (those which arose in or near Antioch); the Western text (Old Latin and Old Syriac); Alexandrian (this is not represented continuously in any one MS, and is really only found by scattered readings in MSS which really belong to other groups; they are in sum, readings that are neither Western, nor Syrian, but differ also from what was most likely the earliest form of the text). Lastly, as Dr Hort termed it, the 'Neutral' text. Other groups however do also exist, e.g. the Caesarean; this was the title given by Dr Streeter to the text that stood midway between the Neutral and the Western, as used by Origen in certain writings when he lived at Caesarea.
The mixture of text that can arise is well demonstrated by the Chester Beatty pap. P45 from Egypt; when this was discovered, it was found that this included writings that were nearer to the Caesarean than any other type, other parts that lay between the Neutral and Western, and also parts that were nearer to the Neutral, but also with a few minor Western characteristics.
The divergences in these different types is discernible, e.g. the Western text is characterised by the freedom of addition - and sometimes omission - and whole verses or even longer passages are found in this which are absent from all other text types. In the case of the Alexandrian, these are found most regularly in the quotations of Origen, Cyril of Alexandria and other Alexandrian fathers, hence the title given to this type. It is interesting to note that it is clear that a principle desire was the correctness of language; because of this, this group is not considered to be of major importance.

There was a long dark 'tunnel period' between the writings of the N.T (New Testament) and these being treated as Holy Writ.
The first earliest papyri is Rylands P52 usually dated ca. 140 CE but this only has just 6 verses of John. In fact the first complete MSS of the N.T are 4th century (Sinaiticus and Vaticanus). All N.T writings were apparently written in Greek - not the language that Palestinian Jews would have used.
Moreover, tampering with the text clearly occurred in this tunnel period. The differences between the Byzantine, Alexandrian and Caesarean texts show copyists changed the text (e.g. Acts 2:17 in the Western text). The 3rd cent. Christian writer Origen condemned those Christians for "their depraved audacity" in changing the text and Jerome told Pope Damascus of the "numerous errors" which had arisen in the texts through attempted harmonising. In 1707 John Mill of Oxford listed 30,000 variants in the different NT texts, and at the beginning of this century with further discoveries of manuscripts, the scholar Hermann von Soden listed some 45,000 variants in the N.T texts illustating how they were altered. Even in the 4th cent. Codex Sinaiticus, containing all the N.T, Professor Tishendorf, the discoverer, noted that it had been altered by at least three different scribes. This demonstrates that the present-day Bible is not and cannot be an "inerrant copy" of the original writings.

Examination of different MSS shows the variants which have occurred in the time of copying.
In 1707 some 30,000 variants were listed from Greek MSS by John Mill; early this century von Soden printed evidence of some 45,000 variants that he had found in N.T MSS.
There are a number of reasons for these variants; many of them are unintentional. One example being mistakes caused by an error of the eye, ie. misreadings that resulted in omissions, repetitions and transpositions of letters, words and even whole lines; this type of variant was really inevitable not only because the copyists were subject to normal human error, but because the task of copying was not particularly straightforward; one example of this being that Hebrew consonants look similiar to Greek uncial letters, particularly when they are carelessly written.
(1)If the eye skipped over a word, letter, word or line(s), the error is 'haplography' ("single writing"); (1a) If it was a case of seeing something twice, the error is termed 'dittography' ("double writing"). One example of this can be found in 1 Thess 2:7 - the difference between 'we were gentle' and 'we were babes' (as per RSV footnote), is whether one or 2 'n's' belong in the Greek. In Matt 27:17, the insertion of 'Jesus' before 'Barabbas' in some MSS may arise through repetition (dittography) of the last two letters of the Greek word 'for you' which in fact was the regular abbreviation for 'Jesus'. In contrast to this, it may in fact be a case of haplography where 'Jesus' has been omitted.
(2)If the confusion is due to similiar endings on two words or lines, so the intervening words are omitted, this error is termed 'homoeoteleuton' ("similiar ending"); if it is the case of omission due to a similar beginning, it is termed 'homoeoarcton'; an example of this arises in the O.T, ie. 1 Sam 14:41 where several clauses have dropped out in the Hebrew between 'Israel' - the LXX and the Vulgate preserve another, possibly the correct reading.
(3)A cause for another type of error was simply the copyist mishearing; if a letter was being dictated it would be inevitable that a scribe would mishear things; such a situation appears to have arisen in Rom 5:1 - 'we have peace' and 'let us have peace' (RSV Footnote) which sounded the same in first cent. Greek. This error was possible in N.T copying but not for the O.T, as there are no rabbinic references to a practice of reading aloud to a copyist.
(4)There were also errors through poor judgement. A copyist might misinterpret the abbreviations that were often used in MSS, especially for 'God' and 'Christ' which were frequently abbreviated. The variants found in 1 Tim 3:16 undoubtedly involved this point.
On occasion a copyist would have to divide a word; as Greek uncials were written continuously, without a break, a scribe introducing his own word divisions would have to decide upon the position of the word-break. It is was not always clear where a sentence ended; Rom 9:5 is a good example of this and is important as it may be a rare occasion of when Paul appears to call Christ 'God'.
(5) Liturgical instructions also appear to have been added in some cases, e.g. Acts 8:37 (RSV footnote) which most likely reflects the baptismal confession in the church of the second cent. copyist.
1 Cor 4:6 is a good example of the errors that could arise when notes were added in the margin or under the text; the phrase 'to live according to the scripture' is literally 'not above what is written'; it is suspected that a copyist made an error in the first verses of 1 Cor 4, then made a note for the next copyist not to repeat this error, but instead, the next copyist not only did this, but also included the instruction which had been left for him.
(6)Deliberate alterations also occur in the text; this is due to a number of reasons.
Copyists made changes for theological reasons, e.g. to remove what appeared to be a contradiction, to expand upon something that he felt was important, to change the meaning to suit his own viewpoint, or changing the statement simply to clarify the meaning. On occasions the copyist might simply make changes to supply a more familiar word, e.g. the unusual verb in Mark 6:20 when Herod was 'perplexed' was changed in later MSS to 'did'. Clarification of a verse can be seen by Mark 14:12 'lest...it be forgiven them' becomes in certain MSS 'their sins should be forgiven them'. In John 5:3b-4 (RSV footnote), there is an insertion to explain the conversation that follows.
When Matt (27:9) quotes an O.T passage which is mostly from Zechariah but it is attributed to Jeremiah, some MSS show that a copyist has attempted to remove this. In Mark 1:2, two statements are brought together, one from Isaiah and the other from Malachi, but Mark attributes both to Isaiah; again some MSS omit 'Isaiah' to try and remove this error.
In time, some copyists felt it would be useful to add further details, e.g. in one Old Latin MS, the two thieves being crucified with Christ are given names in Mark 15:27. In Matt 24:36 Jesus states that even the Son did not know when the parousia was to occur and obviously some copyists felt this impugned Jesus' omniscience, and in some MSS 'nor the Son' is missing.
It is suspected a copyist's marginal protest note has been included in Luke 16:16-18. In v.16 Jesus states that the law and the prophets were only until John, and in v.18, Jesus forbids divorce (against the Deut 24:1-2 ruling), but in v.17 he states that not one dot of the law will pass away; some feel a marginal protest against 16:16 (and possibly v.18) by a Jewish-Christian copyist has been incorporated into the text and hence the contradiction.
The view of the copyist towards Jesus' status is reflected in the MSS; in John 1:18 'the only Son' becomes 'the only God' in some MSS; therefore the Christology of the copyist sometimes led to changes being made on occasion. Heb 1:8 has two different renderings and one of these has the Son being addressed as 'God'. The personal view of the copyist could sometimes result in word changes that drastically altered the meaning of the sentence; in the Western text, the Jews 'act evilly' when crucifying Jesus, but in the Codex Vaticanus, the Jews merely act 'in ignorance'. In Acts 2:17 when Peter explains about the prophecy of Joel - that the spirit would be poured out on all flesh - the Codex Bezae has the noun for flesh in the plural to stress that this promise was for all nations and peoples, and not just the Jews. In Vaticanus, the wounded side of Jesus, as detailed in John 19:34 is also introduced at Matt 27:49.
One of the most significant additions to N.T writing is Mark 16:9-20; here the abrupt ending of Mark has been continued to include post-resurrection appearances by Jesus to his disciples. The critical time for this was most likely ca. 70-ca. 150 CE; at this time Christian writings were not seen as 'Scripture', but 'guides to Christian living' so there was no real difficulty in making changes. Later on, Origen condemned copyists who made deliberate changes for their 'depraved audacity' and Jerome reported to pope Damascus that 'numerous errors' had arisen through attempted harmonisation by copyists.

One rule adopted by those endeavouring to ascertain the original reading is to choose the reading that (a)is the most confused (ii)contradicts or is least likely to agree a statement in another N.T. writing (iii)is shorter. It was usual for a copyist to change a statement to make it clearer, or if it contradicted another passage, or if it could be made to support another passage; a longer passage is therefore most likely the one that has been changed as a copyists would tend to lengthen it to include an explanatory note. The general rule is 'Lectio difficilior probabilior', ie. it affirms the more difficult expression as the one to be regarded as more likely the original.
However, the salient point is if the Bible is meant to be God's infallible guide to humanity, why did so many errors arise, and secondly the fact that copyists felt able to make alterations surely demonstrates the early Christians did not regard the New Testament as 'holy writ'.

The N.T does not present a dogmatic system - it is adapted to its changing environment - Palestinian, Hellenistic Judaism, the Gentiles, sub-apostolic Hellenism and ranging over 75 years; therefore there are many variations and these exist even in Paul's writings, e.g. 1 Thess with Rom.
The earliest collection of sacred writings in the church was the Hebrew Scriptures; Christian preachers based their arguments upon these; they were read in services; the LXX was used in Greek Christian circles.
There is evidence there was a collection of O.T passages that seemed to relate to Jesus - these were quoted as 'proof-texts' by preachers; it is possible that the writing referred to by Papias, supposedly written by Matthew, was such a collection.
Sayings attributed to Jesus, not in the Gospels, have been found on papyrus sheets in Egypt - these are known as 'Agrapha' - unwritten sayings. The title of one sheet begins 'These are the sayings which Jesus the living Lord spoke...'.
Letters of Paul were treasured by the church; they were read in services and collections were made of these; when the Gospels were written, they took their place with Paul's letters although these writings were not deemed equal to the O.T.
About 150 CE, the church began to distinguish between the books that could and could not be read in the church; the basis of recognition was the belief it had been written by an apostle or personal disciple; they should also conform to the orthodox teaching - this was a somewhat circular argument.
The church did not have any uniform agreement though. Heb, Jude, 2 Peter, 2 & 3 John and James and Rev are omitted from some lists. It was not until the mid-4th cent. that there was agreement; the 27 books appear in the proceedings of the Synod of Laodicea (363) and the Synod of Carthgage (397). However the 'Syrian' church of South India still does not have II, III John and Rev. The Ethiopian church has an additional eight though.

One clear indication of how the church was unable to select its canon for literally hundreds of years is shown by the third century apologist, Origen. He had 3 classes of writings - (1)Those uncontested - the 4 Gospels, the 13 letters of Paul, 1 Pet, 1 John, Acts and Rev. (2)The doubtful - 2 Peter, 2 and 3 John, Heb, James and Jude. He cited Hermas and the Didache but does not appear to have accepted them into the canon; he does list Barnabas within the N.T though. (3) Those that were rejected.
In Codex D, Phil, 1 and 2 Thess are missing, as are the 7 Catholic letters, Rev, Acts and Heb. However Hermas, Acts of Paul, Rev of Peter are included. Methodius of Olympus, an opponent of Origen, quotes all the N.T writings as canonical but also the Rev of Peter, Barnabas and the Didache.
Eusebius (330 CE) had three classes of writing - accepted, disputed and those completely rejected. The first set was the Gospels, Acts, 14 letters of Paul (ie. Heb included), 1 Pet, 1 John, and 'if one will' Rev. In the second class, this is broken into two groups - the first set that are still esteemed - James, 2 Pet, 2 John; the second group included the Acts of Paul, Rev of Pet, Hermas, Didache, Barnabas and 'if one will' Rev. He says that some accepted the Gos of the Hebrews. In Eusebius' day, the Catholic letters were still disputed and so was Rev. Cyril of Jerusalem, ca. 350, in the 59th or 60th canon of the synod of Laodicea (after 360) and Gregory of Nazianus (d. 390) there are 26 writings - Rev being omitted. In 367 Athanasius issued his Easter letter and lists 27 writings as the only canonical ones: but in addition to these and rejected writings, he mentions a 3rd group - those that could be used in instruction - Didache and Hermas. Athanasius was the first to name this collection as the 'kavwv' (Canon) and his authority was such that the canonicity of the 7 Catholic letters was rapidly established although Rev was still disputed even at this time. A number of leading Christians did not accept it. There is a list from the 9th cent that omits it and in reality, it was only from the 10th cent that the number of 27 prevails in the Greek church. In the upshot it has taken the church about one thousand years to decide upon its own scriptures. In view of the claims made for it, this is remarkable, to say the least.

Pasted from http://mythofjesus.org.uk/