Greetings,
This is actually recycled material posted a long time ago on a missionary website known for its pathetically misinformed comments about Islam. Last I checked, copy-pasting material from anti-islamic sites rather than formulating your own arguments was against the rules.
First of all, it is the unanimous consensus of the entire Muslim ummah for the past 1400 years that anything which opposes the Qur'an is false. The Qur'an is the final criterion to distinguish between truth and falsehood.
Secondly, most of the people you are citing as 'muslim scholars' are nothing of the sort at all!
Ali at-Tabari was a persian jewish convert to Islam who was a medical physician, not a religious scholars. The philosopher Ibn Sina is likewise recognized only for his scientific contributions; in fact many of his philosophical ideas were denounced by all Muslim scholars as heretical. Al-Mas'udi, the traveller, and Ibn Khaldun the sociologist, were both historians not religious scholars. Sir SA Khan was a recent modernist. Honestly, when this is the kind of list that is composed of so-called 'muslim scholars' it really betrays a large amount of ignorance.
Thirdly, let us examine what the classical sources actually do say about the corruption of the previous scriptures.
From the Tafsîr of Ibn Jarîr At-Tabarî on ayat 2:75:
حَدَّثَنِي بِهِ مُحَمَّد بْن عَمْرو , قَالَ : ثنا أَبُو عَاصِم , قَالَ : ثنا عِيسَى , عَنْ ابْن أَبَى نَجِيح , عَنْ مُجَاهِد فِي قَوْل اللَّه : { أَفَتَطْمَعُونَ أَنْ يُؤْمِنُوا لَكُمْ وَقَدْ كَانَ فَرِيق مِنْهُمْ يَسْمَعُونَ كَلَام اللَّه ثُمَّ يُحَرِّفُونَهُ مِنْ بَعْد مَا عَقَلُوهُ وَهُمْ يَعْلَمُونَ } فَاَلَّذِينَ يُحَرِّفُونَهُ وَاَلَّذِينَ يَكْتُمُونَهُ : هُمْ الْعُلَمَاء مِنْهُمْ . * - حَدَّثَنِي الْمُثَنَّى , قَالَ ثنا أَبُو حُذَيْفَة , قَالَ : ثنا شِبْل , عَنْ ابْن أَبِي نَجِيح , عَنْ مُجَاهِد بِنَحْوِهِ . 1098 - حَدَّثَنِي مُوسَى , قَالَ : ثنا عَمْرو بْن حَمَّاد , قَالَ : ثنا أَسْبَاط , عَنْ السُّدِّيّ : { أَفَتَطْمَعُونَ أَنْ يُؤْمِنُوا لَكُمْ وَقَدْ كَانَ فَرِيق مِنْهُمْ يَسْمَعُونَ كَلَام اللَّه ثُمَّ يُحَرِّفُونَهُ مِنْ بَعْد مَا عَقَلُوهُ } قَالَ : هِيَ التَّوْرَاة حَرَّفُوهَا . 1099 - حَدَّثَنَا يُونُس , قَالَ : أَخْبَرَنَا ابْن وَهْب , قَالَ : قَالَ ابْن زَيْد فِي قَوْله : { يَسْمَعُونَ كَلَام اللَّه ثُمَّ يُحَرِّفُونَهُ } قَالَ : التَّوْرَاة الَّتِي أَنَزَلَهَا عَلَيْهِمْ يُحَرِّفُونَهَا , يَجْعَلُونَ الْحَلَال فِيهَا حَرَامًا وَالْحَرَام فِيهَا حَلَالًا , وَالْحَقّ فِيهَا بَاطِلًا وَالْبَاطِل فِيهَا حَقًّا , إذَا جَاءَهُمْ الْمُحِقّ بِرِشْوَةٍ أَخَرَجُوا لَهُ كِتَاب اللَّه , وَإِذَا جَاءَهُمْ الْمُبْطِل بِرِشْوَةٍ أَخَرَجُوا لَهُ ذَلِكَ الْكِتَاب فَهُوَ فِيهِ مُحِقَ , وَإِنْ جَاءَ أَحَد يَسْأَلهُمْ شَيْئًا لَيْسَ فِيهِ حَقّ وَلَا رِشْوَة وَلَا شَيْء أَمَرُوهُ بِالْحَقِّ , فَقَالَ لَهُمْ : { أَتَأْمُرُونَ النَّاس بِالْبِرِّ وَتَنْسَوْنَ أَنْفُسكُمْ وَأَنْتُمْ تَتْلُونَ الْكِتَاب أَفَلَا تَعْقِلُونَ } . 2
It was reported from Muhammad bn Amr from Abu Aasim from Eesa from Ibn Abi Najih from Mujahid that he said regarding this verse "Those who used to alter it and conceal the truth - they were their scholars."
It was also reported from As-Suddi that he said regarding this verse, "It was the Tawrah they altered."
It was also reported from Ibn Zayd that he said regarding this verse, "They altered the Tawrah that Allah revealed to them changing what was declared lawful therein to unlawful, and the unlawful to lawful, and changing what was declared truth therein to falsehood, and the falsehood to truth. So when a person seeking the truth comes to them they judge his case by the book of Allah, but when a person comes to them seeking to do evil with a bribe, they bring out the other book which says he is in the right. When someone comes to them neither seeking the right nor with a bribe, then they enjoin righteousness on him. This is why Allah told them "Do you enjoin righteousness on the people and forget yourselves, while you recite the book? Have you no sense?" (2:45)
The same thing is found in Tafsîr Al-Qur'ân Al-'Adhîm by Ibn Kathîr and also in Jami Ahkâm Al-Qur'ân of Al-Qurtubî.
In fact the former mentions:
فَلَا شَكّ أَنَّهُ قَدْ دَخَلَهَا التَّبْدِيل وَالتَّحْرِيف وَالزِّيَادَة وَالنَّقْص
Without a doubt they have been altered, corrupted, added to and deleted from.
Here is a fatwa concerning the NT:
Question: I was speaking to a Christian friend, and mentioned to him that the New Testament is not the Gospel of Christ (peace be upon him) in its original form. He refused to accept this. Being a Christian, he does not accept statements from the Qur’ân and Sunnah as evidence. What can I tell him?
Answered by Sheikh Ahmad al-Qâdî, research fellow at al-Imam University It has been generally accepted by Christians for ages that the word “Gospel” does not refer to one specific text, but rather to four gospels selected out of hundreds, the others of which were declared unauthentic. Consequently, these four gospels – Matthew, Mark, Luke, and John – are not the revelation that was revealed to Christ (peace be upon him). Instead, they are accounts of Christ’s life and quotations of some of his statements that were recorded by others, some of whom never met him personally.
Leading Christian authorities acknowledge that there are differences and variations between these four gospels. For instance, the “Dogmatic Constitution on Divine Revelation” of the Second Vatican Council states: The sacred authors wrote the four Gospels, selecting some things from the many which had been handed on by word of mouth or in writing, reducing some of them to a synthesis, explaining some things in view of the situation of their churches and preserving the form of proclamation but always in such fashion that they told us the honest truth about Jesus. For their intention in writing was that either from their own memory and recollections, or from the witness of those who “themselves from the beginning were eyewitnesses and ministers of the Word” we might know “the truth” concerning those matters about which we have been instructed (see Luke 1:2-4).
This is a clear admission that the four gospels included in the New Testament are the work of men and are not the word of God.
This is the reason why there are differences between them and dozens of contradictions. A detailed exposition of these contradictions is given by Rahmatullah al-Hindî in his book Izhâr al-Haqq.
For us as Muslims, the greatest evidence that the New Testament is not the uncorrupted word of God is that the claim of Jesus’ divinity and the claim that Jesus (peace be upon him) is the son of God are to be found within it, along with the doctrine of the Trinity and other beliefs that contradict with the monotheism that was brought by all the Prophets (peace be upon them all).
That should clarify this matter.