All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
The Quran is the Book of Allaah and the last revelation which abrogated all the previous divine books. There is no doubt that this book is preserved from any alteration and falsification. It was transmitted to the Muslims, generation by generation, by absolute evidence. Since its revelation, it was kept intact in its written form as well as being memorized [by millions of Muslims], young and old people, males and females, Arabs and non-Arabs. No one could add a letter to it or remove a letter from it. The differences that might happen in the interpretation of the Quran does not mean that it was falsified, as interpreting the meaning of the Quran is not considered as adding to it or taking out anything from it.
The difference in the interpretation of the verses is of two kinds:
Similar interpretations: [Different interpretations but similar in meaning], like when there is a difference in the term. Example: The true path (As-Siraat Al-Mustaqeem) is interpreted to mean the Quran or Islam. Both interpretations are correct. This kind of interpretation is not a difference in reality.
Second interpretation: Contradiction in the interpretation, in a way that the first meaning contradicts the second meaning. So this is the real difference. For instance the interpretation of menses in the verse of Allaah (which means): {And divorced women shall wait (as regards their marriage) for three menstrual periods.}[Quran 2:228] Some interpreters of the Quran interpreted it to mean the beginning of menses and some interpreted it to mean the beginning of being pure from the menses. This is because the word in the Arabic language accepts both meanings. So when this kind of difference of interpretation occurs, then in order to favour one meaning over the other, one resorts to another text in the Quran or in the sayings of the Prophet and the like.
The verses of the Quran are interpreted by other verses or by a saying of the Prophet . If there is no other verse to interpret the first verse and no Ahadeeth (Prophetic narration), then one has to resort to the sayings of the Companions as they witnessed the revelation. If there is nothing of the above at all, then one interprets the verse according to the meaning of the words in the Arabic language as the Quran was revealed in Arabic. Therefore, there are some requirements when interpreting the Quran and there is even a science called the Principles of Tafseer (interpretation of the Quran).
As regards some people using verses from the Quran [if they can find any that could apply to them] to justify their conduct, then we can not rule by this conduct that the deficiency is in the Quran. Rather, it is by the Quran that we judge whether or not the conduct of people is proper.
According to Tyndale House Publishers, Inc. (Wheaton, Illinois, USA), “The Bible may look like one book, but it is actually sixty-six books in one. Thirty-nine books make up what we call the Old Testament, and twenty-seven make up the New Testament. It is possible that more than forty writers were used by God to write all sixty-six books.” Based on the above, the Bible was never ever narrated by God nor was it written by Him.
By any objective criteria, the Bible is a book containing a compilation of stories, legends, folk tales, folklore, myths, sagas, narratives, poetry, fragments of scriptures (fragments from the Psalms, the Torah, and the Injeel), letters (esp. in New Testament), visions, dreams, accounts of events from doubtful sources (not eye witnesses), editors’ or scribes’ notes, as well as human errors.
For those who believe in it, the Bible is a book that has historical, cultural, moral and ethical value, and a source of spiritual teaching and guidance. It is a book held in high esteem, primarily by Christians who see it as a divine book and the source of their religious beliefs. But, objective analysis proves that the Bible is only a book with many limitations and imperfections which disqualify it from being called “The Word of God.” Whoever makes such a claim then the burden of proof rests upon him!
On the contrary the Glorious Quran is the Speech of Allaah that was revealed to the Prophet Muhammad by the angel Gabriel, and later compiled in book form and remained in its original form until now. It remained preserved because Allaah promised the Muslim nation to preserve it saying (what means): {Indeed, it is We who sent down the message [i.e. the Quran] and indeed, We will be its guardian}[Quran: 15:09]
The Quran remained preserved in its original form through the centuries despite the weakness that the Muslim nation underwent, the vanishing of the Muslim caliphate, and the disputes and differences amongst the Muslims. Despite all this, the Quran remained preserved and protected by Allaah, which is one of its miracles.
Finally, we invite you to embrace Islam in order to be happy in this life and in the Hereafter. You could refer to Ahmad Deedat's site in order to check some debates that he held with outstanding ministers.
You could also refer to Fatwa: 88906 on Islam that it is the religion of all the Prophets, and Fataawa (plural of Fatwa): 88276, 88176, 86091 and 82037 about an introduction to Islam.
Allaah Knows best.