I forgot to add I don't understand the motive behind Muslim's trying to limit the scope of Jesus' message. I suspect it has to do with the idea that the Quran is meant for all and that therefore Jesus' must have been a regional message, but interestingly enough I am not aware of anything explicit in the Quran that indicates the "Injil" was only meant for the Jews.
I won't try to explain this as it would take too long. But in brief, It is the 1 God, the message is the same from Adam (a.s) throughout the ages to all prophet (peace be upon them all) and those messengers with the Scriptures, the Torah, the Psalms, the Bible and the Qur'an. Why did the Jews stop at the Torah, and the Christians with the Bible? So with every new revelation that came, the followers of the Word of God should have accepted and incorporated it into their life.
In my experience Muslims are for the most part very diligent and careful when it comes to interpreting the Quran. A holistic approach is taken, hadith is consulted for additional support, and the soundness of argument is based logically. I don't understand why then the diligence seems to wane when addressing the sacred text of another faith. I understand it may not be part of your religion, but just as a matter of correctness the same approach should be applied.
The problem as I see it is that the Bible is not quite the same. If anything, it would be more closely associated to hadiths as it is an account of what happened and was said written by people (an interpretation) of what happened, or a narrative of what happened. The Qur'an on the other hand are memorized words of Allah, written and compiled within the lifetime of the prophet which exist until today. Translations are made using the original text as opposed to translated words from millennia passed. And the hadiths are actions and advises from the prophet pbuh that complements the understanding of the Qur'an. These two sources are not available in the Christian's faith so the same approach cannot be undertaken.
So when a muslim were to compare statements from the Bible, they only have the Qur'an to refer to. Although muslims believe that the Bible in its original form were the words of Allah, but the copies we currently have in circulation have been tampered with to the point of us (muslims and Christians) having this gap in belief. How could we then take into account what is written in the Bible except to believe that what Jesus spoke was true, but not necessarily what evolved from his teachings today. In another word, if we wanted to know what the context of the Bible was, we can get it from the Qur'an. Only difference is that it was told by a different prophet and that it also included laws that govern community living.
