It is not hiding to every Muslim that wars against Islam, its Sacred Book, and its Noble Messenger have never ceased since the very early days of this religion. This attitude of the haters of truth and belligerent bigots of falsehood is not unusual. However, Islam teaches its followers to always observe justice and fairness, even with their enemies. Muslims cannot transgress the limits of Allah under the pretext that their enemies have done so.
Regarding this issue, Dr. Salah Al-Sawy said,
We do not accept the statement that the Torah or the Gospel can be used as toilet paper. These Scriptures contain some of the words of Almighty Allah.
The distortion in these books does not mean they were completely changed; it means they were altered through additions and omissions. Nevertheless, there remain some of the words of Allah in these books. Hence, it is not permissible for anyone to belittle these books in this manner.
The stance of our Sharia with regards to believing or belying these books should be considered: We are enjoined to abstain from testifying to the truthfulness or falsehood of the People of the Book, lest we call a falsehood a truth or call a truth a falsehood. So, we have to refrain from believing in or denying these books, because they contain some of the words of Allah, besides the human additions and distortions.
Similarly, it is not permissible for anyone to belittle these books altogether, because Allah’s words might be among what is belittled.
As for the enmity of some foolish people toward the Qur’an, Almighty Allah will defend His Book against those who encroach upon it. Allah Alone is sufficient for us, and He is the best disposer of our affairs.