Abdul Saleeb, in "Islam's Theological Challenges," writes of the problem of Muslims claiming the Bible has been corrupted:
1. The Qur’an refers to the Bible as “The Book of God,” “The Word of God,” “A light and guidance to man” (Sura 2.41, 89, 101), confirming its divine origins.
2. The Qur’an confirms previous Scriptures (Sura 2.41, 89, 101).
3. Muslims are commanded to believe in the previous Scriptures (Sura 2.136).
4. Muhammad is encouraged to test the genuineness of his own message with the contents of the Jewish and Christian Scriptures (Sura 10.94).
5. Christians and Jews are commanded to stand firm on the Law and the Gospels (Sura 5.71; cf. 5.50).
6. Very few changes to the Scriptures, if any, happened after AD 600.
> How does one counter the numerical discrepancies they cite?
Numerical discrepancies are often scribal errors that with only a little effort can be figured out.
> Matthew and Luke's accounts about Jairus
We know from the writings of Plutarch, who wrote over 60 biographies in the same era that the Gospels were written, that in those days it was not only acceptable but expected that certain practices were part of the work:
1. Transferal (attributing words spoken by one person to another)
2. Displacement (placing something spoken in one context to another context)
3. Conflation (combining elements of two different events or people as one)
4. Compression (describing events as taking place in a shorter period of time than actual)
5. Simplification (omitting details in order to focus attention)
6. Expansion of narrative details (creative reconstruction and free composition of plausible circumstances)
7. Paraphrasing (creative retelling to emphasize a point)
8. The law of biographical relevance (the addition or omission of biographical information according to the purpose of the author)
As Mike Licona writes, "The Gospels writers also follow these practices and use these literary devices. It would be absurd to suppose that the NT Gospel writers could have learned to write Greek and cope with written source material while remaining outside the pervasive influence of their culture. The differences between the Gospels can quite easily and rightly be appreciated and/or resolved in light of the literary conventions of ancient biography and historiography."
Craig Keener, in "Christobiography," writes: "Studies of contemporary ancient biographies show that ancient biographers displayed different levels of flexibility in appropriating their sources. Nevertheless, such levels of deviations were common textual phenomena in ancient biographies. The parallels and variations that we find in the Synoptic Gospels would have been analogous to other similar literary works of the time. Just like Tacitus and Suetonius would not have invented their reported rumors about Caligula, Nero, and Domitian, the Gospel writers also would not have invented new stories (i.e., events not in their sources) about Jesus. Therefore, such differences as chronological displacement, conflation of material, and simplifying of narratives in the Gospel accounts would have been typical of the biographical genre and expected by ancient audiences."