For Muslims the Qur’an is only truly the Qur’an in its arabic form. This is because of their beliefs surrounding how the Qur’an came to be.
The belief that the Qur’an is a literal transcript of the Word of God from a safely preserved tablet (lauh mahfuz) in heaven revealed to Muhammad in Arabic
This belief says that there is a tablet in heaven in arabic and Muslims believe that the Qur’an they read in Arabic is exactly the same as that heavenly tablet.
A second reason is that, as we metioned previously, the Arabic itself is supposed to be proof of its divine nature. The moment you translate it, no matter how good the translation, you lose the argument for perfection.
It is understood from those explanations that one of the reasons why the Quran was sent down in Arabic is the special position of the language of Arabic – which had the ability to reflect the wonder of the Quran, which is a mental, spiritual and lingual miracle.
The Qur’an in any other language then, is at best an approximation.
By contrast the Bible has a long history of translation. Why so? The Baptist Confession of 1689 (following Westminster) says,
But because these original tongues are not known to all the people of God who have right unto, and interest in, the Scriptures, and are commanded, in the fear of God, to read and search them, therefore they are to be translated into the language of every people unto which they come, that the Word of God dwelling plentifully in all, they may worship him in an acceptable manner, and, through patience and comfort of the Scriptures, may have hope.
The argument is simple, if there is a controversy or disagreement go to the original languages but everyone has the right to know the Word of God and therefore it should be made available in their own language. Again the confession makes it dependant on the work of the Spirit to illuminate the hearts of the reader or hearer. As such it is the active work of the Holy Spirit that brings the beauty of the Word to life, not the language or the words themselves.