Men of the stature of Noah (sws), David (sws) and Lot (sws) are projected in the Bible as having committed indecency, incest and adultery. These must be lies, but why would the Christians change their scripture to tarnish the images of their holy men and yet, on the other hand, elevate saints and popes as “impeccable”?
There is no doubt about the fact that the Biblical allegations against the prophets are lies. The Qur’an informs us about the fact that the prophets were the chosen people of the Almighty because of the highest level of morality they were able to achieve. The Qur’an, for instance, says:These are some of the Prophets on whom Allah bestowed His favours from among the descendants of Adam and of those whom We carried in the Ark with Nuh, and of the descendants of Abraham and Israel, and of those whom We guided and chose. Whenever the Revelations of the Compassionate (Allah) were recited to them, they fell to prostrate and weep. (19: 58)
Allah chooses His messengers from among the angels and from among the human beings, for surely Allah is All-Hearing, All-Seeing. (22:75)
The second verse clarifies that if Allah Almighty chose them for the most significant obligation of prophethood, it was on merit, because He is All-Knowing and All-Seeing.
As for the question, “why Christians accepted the perverted picture of their prophets while they exaggerated the status of their saints”, I can’t say much with confidence. I would trace the origins of this problem in their tendency of following their elders blindly. Once you stop being critical about what the elders have given you in the name of religion, you can accept everything – good as well as bad, without much trouble. It seems that some unscrupulous scholars amongst the Jews deliberately inserted a tarnished image of the prophets so as to be relieved of the tension of expectations from them, which the common man naturally had, given the high standards of morality set by the prophets. In a situation where religious leadership is devoid of true religiosity, the common man can be highly critical of them. The scholars, in such cases, are left with two options: either admit their failings, make a firm resolve to improve or bring down the ideals set by prophets from their lofty status. Some of the earlier Jews, it seems, sadly, opted for the latter option. Religious Jews and Christians of later times believed in divine origins of the entire text. As a result, the Christian world (as well as the Jewish) is divided into two broad groups: those who believe that the entire Bible is God-inspired, and those who believe that there is no truth in the claim that the Bible has divine origins.
It is only the Islamic view of the Bible that makes sense. According to the Islamic understanding, some books of the Bible were most certainly originally from God; however, some of them have undergone changes, because of deliberate manipulation or otherwise.
Courtesy:http://www.islamicissues.info/qa_question.php?qid=125