Muslims believe that God sent prophets with the message of Islam to different nations in different periods of history. Islam considers that there were several holy scriptures that were revealed to the prophets, containing the laws and codes of conduct of Islam. Muslims believe that the Qur'an, revealed to the prophet Muhammad, was the last of the Holy Scriptures. The Qur'an contains a message that is universal, rather than limited to a single nation or time period. Muslims also consider that the scriptures previous to the Qur'an were either corrupted or lost altogether. However, respecting and following all of the Holy Scriptures in their original forms (clarified by the Qur'an) is one of the fundamental beliefs of all Muslims.
Of the three holy books that are mentioned by name in the Qur'an, the Torah is the one that was used the longest. Muslims consider that the prophet Moses received the revelation of the Torah and that he and his brother Aaron used this divine scripture to spread Islam to the Children of Israel. The Qur'an warns that the prophets sent to the Hebrews were sent with the warning that the Torah contained corruptions in its text. Muslims believe that the Torah and the Law of Moses was taught to Jesus in their original form, and that this was the last case of it being taught in its true form. Another of the Holy Scriptures that is explicitly mentioned in the Qur'an are the Psalms. Muslims consider that the Psalms are a holy scripture that was revealed to the prophet David. Muslims have long considered that the Psalms are holy songs to praise God. Many Muslim scholars consider that the Psalms that exist today are commendable and worthy of praise. However, most Muslims consider that there are some of the current Psalms that were written after David's time and that they were not revealed by God.
Muslims believe that Jesus received the Gospel, a holy book mentioned in the Qur'an (Injil.) Muslims consider that this was an original Gospel that was directly written by God and given to Jesus, the last prophet that God sent to the Children of Israel. This Gospel is different from the New Testament, written after Jesus' time and corrupted afterward. Muslims consider that the current Gospels in the New Testament are not the divinely-revealed book, but documents of his existence written by the people around him and after him. Muslims consider that the New Testament contains elements of the teachings of Jesus, but does not represent the Gospel that God revealed to Jesus. The Qur'an also mentions the book of Yahya, a religious text that has been lost. This religious text is part of the faith of the Sabians and Mandaeans, mentioned in the Qur'an as people that will be rewarded by God (along with Christians and Jews.)
-- Al Arabiya Digital