Perhaps, here it may be helpful to explain some Muslim beliefs that informs hasantas’ understanding of the Bible. Unfortunately because of his biased closed mind and his intentions (it is not part of an inter-religious understanding but he is just trying to prove Islam is superior to Christianity), he is unable to escape from the following misconception.
Islam belief is that the Quran is written by God himself and thus, cannot be changed. Therefore the only authentic Quran is an Arabic Quran (see my previous post in the same thread). So, for the Gospels to be translated from its source language would be (to a Muslim) a sacrilege for changing the word of God.
Also, the Muslims have two levels of scriptures. First there is the Quran, which is written by God himself and is the ultimate benchmark against which everything else is measured to determine authenticity. Secondly, there are the Hadiths and the Sunnah. Hadiths are stories to illustrate the way the Prophet implemented the Quran while the Sunnah is considered the biography of the Prophet. Hadiths number 30,000 and each need to be validated against the Quran to determine authenticity. Different scholars therefore have different classifications of authenticity, ranging from sahih (authentic) to mawdu (fabricated), depending on how much they agree with the Quran, or contradict it.
Now, the Muslims see the Gospels as either stories about Jesus or the biography of Jesus. Therefore, the Gospels are at the same level as the Hadiths and the Sunnah. Similarly, parts of the Pentateuch would be the Hadiths & the Sunnahs for Moses. The Bible is therefore not at the same level as the Quran and would need to be validated against the Quran for authenticity as the Muslims have done with the Hadiths.
I hope this explains how Muslims like hasantas view the Gospels. You see, Muslims are in a conundrum. They claim that they supplant Christianity. Which means their scriptures are more authentic than Christian scriptures. But their scriptures differ from Christian scriptures. So, if their scriptures are authentic, then Christian scriptures must have been falsified. But how does something which came earlier (the Bible) falsify something that came later (the Quran). So, the myth of an earlier authentic scriptures which the Jews & Christians falsified emerged.
Muslims believe in four messengers (rasul: these are nabi (prophets, who were sent by God) who delivered written revelations. They were Musa (Moses), with the Torah; Daud (David) with the Zabur (interpreted as the Psalms); Isa (Jesus) with the Gospel (note the singular) and Mohammad with the Quran. Other traditions also include Adam and Ibrahim (Abraham) who were both given scrolls by God. The Torah and the Gospel mentioned here are not the same as those in the Bible today because those in the Bible have been falsified. This stance allows Muslims to accept that the Torah and the Gospels have some elements which are authentic but as a whole cannot be accepted.
I have not been able to trace the nature of the falsification. Some have pointed to the translation of the Bible from the original language as the falsification involved. Some question how can there be four Gospels (after all, Mohammad had only one Sunnah). I have also often asked before we start any debate for a list of which verses in our Gospels have been falsified but has never received any. So, I endure the frustrations of the false verses changing from one debate to another to suit the debater.
As always, none of the falsifications or the existence of an earlier authentic written revelations have been backed up by facts. They seem to be true because only the Quran is authentic and so anything that contradicts the Quran has to be false.
We were always lumped together weren’t we? Maybe again the influence of Waraqa - it is hard to differentiate if your teacher of all things Jewish & Christians is half-way between both