Qur’an 2.4 says: “(it) is for those who believe what’s been revealed to you (Muhammad) and what’s revealed before your time.” Clearly what’s been revealed to you is the Qur’an. There are a couple of interpretations regarding what’s revealed before your time. One is that it represents scriptures of all major religions. The other interpretation is that it represents the Bible. The majority of traditional Islamic scholars believe it is the Old and New Testaments of the Bible, but they also insist that the Bible is terribly corrupted. They therefore teach that Muslims do not have to read the Bible. Many verses they quote in the Qur’an for the corruption of the Bible indicate the misinterpretation or misconduct of the Jews and Christians, and some corruption in the extra-Biblical books such as Midrash, but never indicate the corruption of the Bible proper. This is validated by archeological findings on the manuscripts of the Bible. Also, for the Qur’an, there are numerous misinterpretations and misconduct on the Muslim side, and corruption in the lower level scriptures like Hadith or Shariah. Traditional Islamic interpretations believe certain Qur’anic verses were abrogated and, add additional phrases and sentences to the Qur’anic verses so that the texts of the Qur’an become consistent with their own traditions. This is called eisegesis instead exegesis, and should be avoided for interpretations of any scriptures by all means.
Why now do Muslims not follow the teaching in the Qur’an to read and believe the Bible? It is clearly because they are taught WRONG by imams and Islamic religious leaders.
It is critical for Muslims and the relations between Islam and Christianity that Muslims follow what Qur’an says instead of following just what their leaders teach them.
Christians should read the Qur’an and Muslims should read the Bible. That should be beginning of understanding between Christians and Muslims.