when were the books of the new testament finally assembled into the
new testament?  do we have any idea who chose which books would go in
there or why the gospel of thomas was excluded?

Heloo Yakker~

In A.D. 140, an anti-Semitic heretic called Marcion was the probably
first to form a list of what he  considered the ?official? New
Testament canon.  Marcion predictably edited out everything Jewish
from the texts. However, by this time, the four gospels (Matthew,
Mark, Luke, and John) are an integral part of every Christian church.
By A.D. 200, the church was using all the books that are now part of
the New Testament. Although some people of this era argued that
additional books should be included in the NT, The Gospel of Thomas
was not one of them.

In A.D. 367, Bishop Athanasius of Alexandria announced the first
official list of books to be included in the New Testament; they are
the 27 books we know today.

Over the years, church leaders have tried to weed the good books from
the bad, to ensure that the NT was as pure as possible. Here are the
factors they considered:


CREDIBILITY. When the gospels were written, many people were still
alive that recalled the events depicted in them. Those writings found
false were automatically eliminated.

WORD OF GOD. Did they claim to be the word of God? If not, they were rejected.

WRITTEN BY AN APOSTLE. Was it written by an apostle or a close
associate of an apostle? This was considered helpful for inclusion.
While this factor may be considered unfair, it was one way for
Christians to ensure that the information passed on to them was
correct. One would not expect an apostle to lie, after all.

AGREEMENT. Whether or not the book was in agreement with The Old
Testament also was factored in. Also, was it in agreement with NT
books already scrutinized and accepted?

ACCURACY OF TEXT. Texts were also compared to the earliest examples.
There are thousands of copies of the New Testament books, so it was
fairly easy to see which copies were accurate and which were not.

CONSISTENT. Were the books consistent with Jesus? teaching? Many books
were rejected because they obviously did not concur with Christ?s
message.

HISTORICAL ACCURACY. Books with serious historical inaccuracies were
also rejected.


Even in ?its day,? the Book of Thomas was never seriously considered a
possible candidate for inclusion in the NT. Thomas never passed the
above tests.
Only three copies of The Book of Thomas survive, and its date of
origin is in great dispute. Many scholars believe it to be a mid-2nd
century creation.


For more information, you may enjoy these articles:

* "How Were The Books of the New Testament Chosen?" The Daily Camera:
http://www.thedailycamera.com/bdc/religion/article/0,1713,BDC_2477_2869274,00.html

* "The Gospel of Thomas:" http://www.users.zetnet.co.uk/kking/thomas.html


Regards,
Kriswrite


SEARCH STRAGEGY:
"New Testament" canon
://www.google.com/search?hl=en&ie=ISO-8859-1&q=%22New+Testament%22+canon

"New Testament" chosen
://www.google.com/search?q=%22New+Testament%22+chosen&hl=en&lr=&ie=UTF-8&start=10&sa=N

"New Testament" Thomas
://www.google.com/search?q=%22New+Testament%22+thomas&hl=en&lr=&ie=UTF-8&start=10&sa=N

"Book of Thomas"
://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&q=%22Book+of+Thomas%22+&btnG=Search

Some time after the books in the New Testament had been written, the
leaders in the Christian church prayerfully evaluated - for some time
- which ones were inspired by God and which weren't. The ones that
ended up being included were those four Gospels, Acts, and the letters
we know today. They became generally accepted throughout the church,
and were eventually announced as the books comprising the NT.

Kriswrite's answer, however, is much more thorough and detailed; I
just added a little bit I knew about. Hope it helps!

-Gamaliel

i found this to be a particularly good link:

http://www.infidels.org/library/modern/richard_carrier/NTcanon.html

here is a link to one of the best articles on your question. the link
is to part 1, but you can jump to any of the five parts from there...
Your question is answered in part 5, but the other parts are quite
fascinating. This write up is good because it compares both the
"historical" and "traditional" views..
~~~ Enjoy~~

http://www.straightdope.com/mailbag/mbible1.html

the parts are as follows:

Part 1 - Who wrote/compiled/edited (and when) the first five books of
the Bible, called the Torah or Pentateuch or Five Books of Moses?

Part 2 - Who wrote/compiled/edited (and when) the various histories in
the Old Testament (such as Judges, Kings, etc.)? (This section will
also include a brief essay on the problems inherent in dating ancient
events.)

Part 3 - Who wrote/compiled/edited (and when) the various prophetic
books (Isaiah, Jeremiah, etc.) and the wisdom literature (Psalms,
Proverbs, etc.) in the Old Testament?

Part 4 - Who wrote/compiled/edited (and when) the various New Testament Books?

Part 5 - Who decided which books should be included and which excluded
from the Bible(s)? Why are there differences in the Bibles for
Catholics, Protestants, and Jews?

It's also interesting to note that Martin Luther wanted to change the
New Testament Cannon during the Protestant Reformation.  He wanted to
remove Hebrews because the author is not known, James because of its
strong references to good works ("Faith without works is dead"), and
Revelation because he felt that its claim of John's authorship was
false.

In his famous German translation of the Bible, he places these books,
along with Esther, in an appendix.  (Luther's German translation was
perhaps the best translation of the Bible into a modern language until
very recently.  Most scholars agree that it was far better than the
1611 King James)