We have much more confidence in reconstructing the original Bible than we are the original Quran.
We no longer have the originals with us
We no longer have original scriptures with us. In the past paper was not available and whatever had to be written down were written on other natural materials, which would decompose after some time. Before they totally compose, one has to copy the whole thing down on another material in order to preserve the writings. That is why there is no way to access the original writings of the Bible.
There is also no way to access the original writings of the Quran as revelations were written down on decomposable materials. “The Koran was collected from chance surfaces on which it had been inscribed: from pieces of papyrus, flat stones, palm leaves, shoulder blades and rib of animals, pieces of leather, wooden boards, and the hearts of men.” (Concise Encyclopedia of Islam)
Comparing the confidence in reconstructing the original document
Because we do not have the original writings with us, we need to find ways to confirm that the copies we have today is the same as what was originally handed down.
In the case of the New Testament, we have a high level of confidence that the copies we have today is almost identical to what was originally recorded.
The Quran has much less number of copies because an effort was made in the past by Uthman to create an “official” copy of the Quran and to destroy all others.
The collection as it is now was compiled by his followers a few years after his death in 632. An authorized version was produced in the early 650s by a group of Arabic scholars under Uthman ibn Affan. They attempted to destroy all other versions, but some survived and are now accepted. (Source : Encarta Encyclopedia)
Because we only have a few copies of the non-Uthmanic version, the confidence of reconstructing the original Quran is much less than the Bible.
Comparing the gap between the events and their writings
The gap between the earliest available manuscript and the time of writing is important. If the gap is large, there is greater tendency for errors to arise with many times of copying and re-copying.
The New Testament was written during the period from AD 40 to 100 and the earliest copy of the New Testament we have is the John Ryland manuscript, which is dated AD 130. Therefore the gap is less than 100 years.
Reference
The time gap for the Quran is more than 100 years.
Muslims believe that they have a copy of the Quran that was produced by the third Caliph Uthman. There are at least 20 manuscripts that claim to be the Uthmanic manuscript. One is on display at the Topkapi Museum in Istanbul while another is in the Soviet State library. But assuming that one of them turns out to be the genuine copy by Uthman, there is a gap of over 100 years from the date of this manuscript to the death of Muhammad.
The choice of what to include in the Bible was through the acceptance of the people at that time. The choice of what to include in the Quran was through the decision of a committee.
How were the New Testament books chosen?
How were the Old Testament Books chosen?
The choice of what to include in the Quran was not done through acceptance of the community but rather through the work of a committee.
More than one copy of the Quran
The Quran we have today is not the only Quran that has existed in the past. We know from Islamic history that there were more than one copy of the Quran with serious differences between them. The first official copy of the Quran was completed when Abu Bakr was still Khalifa. Another copy was made by Muhammad’s secretary, Ubai b. Ka’b. In addition to these, we know that other collections were made by Ali Ibn Abi Talib, Muhammad’s son-in-law, and by Ibn Abbas. (Source : )
Early Qurans were not identical
Muslim response
Muslim tells us that umar bin al khattab was so much offended at the way in which hisham bin hakim recited surah XXV, Al furqan, that he took him by the cloak and brought him to muhammad to complain of it. After hearing both men repeat the surah, muhammad declared that both were right, and asserted that the “Seven Readings” were all alike admissible!
Christian response
We know from Muslim tradition that these copies were not identical. Differences between collections were so great that Muslim soldiers from Iraq who followed Ibn Mas’ud’s collection and the soldiers of Syria who followed Ubai’s collection, accused each other of lying. The hadiths told us that each side heard things that they have not heard in the Quran.
It is not true that the differences in the Quran were merely differences of dialects and methods of recitation. Muslim tradition tells us that there were differences in the text itself.
‘Yazid b. Ma`awiya was in the mosque in the time of al Walid b. `Uqba, sitting in a group among them was Hudaifa. An official called out, ‘Those who follow the reading of Abu Musa, go to the corner nearest the Kinda door. Those who follow `Abdullah’s reading, go the corner nearest `Abdullah’s house.’ Their reading of Q 2.196 did not agree. One group read, ‘Perform the pilgrimage to God.’ The others read it ‘Perform the pilgrimage to the Ka`ba. (p. 143, Abu Bakr `Abdullah b. abi Da’ud, “K. al Masahif”, ed. A. Jeffery, Cairo, 1936/1355, p. 11)
According to Nisaí, certain words occurred in hisham’s version which were not in what others professed to have learned from muhammad. ubai is represented by nisai as saying that the fact that others repeated verses in a form different from that in which he had learnt them gave him quite a shock.
Effort by Uthman to standardize the Quran
Because of the differences in the Qurans, Uthman instructed his men to send for the variant copies so that he can standardize them into one copy. Uthman ordered all the variant copies to be destroyed.
“Uthman sent to every Muslim province one copy of what they had copied, and ordered that all the other Quranic materials, whether written in fragmentary manuscripts or whole copies, be burnt.” (Source : Sahih Bukhari, Vol 6, Pg 479)
Therefore we see that the choice of what to include in the Quran and what to exclude to remove the variants was done by a committee commissioned by Uthman.