Many muslims consider the Bible (which consist of Old Testament and New Testament writings) is unlike the Qur’an, they are not God’s direct speech, but are just like the Hadiths that is the Bible were written-collected by men, and are based on the sayings-teachings of the prophets. Just as the Hadiths are with the Prophet Muhammad (peace be upon him).
Muslims also do not consider those who transmitted or collected the sayings-teachings were inspired by God. They were all human and prone to errors and mistakes. The Muslim Scholars took a great care to make sure that the collection of the sayings by those men were authentic teachings of the Prophet himself.
Even so Muslim scholars then develop a methodology to authenticate the collection most important is
The collection must contain who actually collected the saying-teachings, and who passed them on, and who actually made the original statement that was passed on. It is called the chain of transmission or the Isnād إسناد : a complete line of transmission.
Muslim scholars even go as far as checking the biography of the transmitter names, where they lived, when they were born, when they died and go further whether a person in the chain, could have been known as untruthful.
From this method the scholars then classify different types of Hadiths
Requirments for a Sound (Saheeh) Hadiths:
- Each reporter should be known as pious and trustworthy people
- He/She should be known to be truthful in his narration, to understand what he narrates
- He should have met the person he narrates from
- He/she should know how a different expression can alter the meaning
- He should know how to report the Hadiths verbatim not just its meaning
- Its source is known
- Its reporters are unambiguous
- A Hadiths that fails to meet the status of Hasan
- Could be a break in its chain
- One of the narrators has bad character such as: lying, excessive mistakes, opposition to a more reliable narration, involvement in innovation, or ambiguity surrounding his person
- The text goes against the established fundamental norms of the Qur’an and the Prophet’s sayings.
- It reporters include a known liar.
- They are also known by their discrepancies related to time and historical events.
Here is more elaborate example on How did Muslim scholars sift through the masses of Prophetic reports to single out the authentic ones
In the case of the Bible writings, we literally do not know who was passing the stories and whether they’re reliable people even worse we don not know the original source because many of them are anonymous writings or pseudepigraphica (Gr: ψευδής, pseudes, “false” and ἐπιγραφή, epigraphē, “name” ). For example all 13 of the letters attributed to Paul are pseudepigraphical. In another example like the book of Isaiah, modern critics have rejected the idea of prophet Isaiah’s authorship but rather anonymous scribes of men.
All this problems stem from the facts that the Bible has no proper documentation regarding its sources and chain of transmissions like in the collection of the hadiths. We can not be certain who were the authors nor there biographies of the transmitters.
This leave us in great doubts whether the Bible contain the actual teachings of God.