Muslims have something that offers the clearest proof of all - The Holy Quran. There is no other book like it anywhere on earth. It is absolutely perfect in the Arabic language. It has no mistakes in grammar, meanings or context. The scientific evidences are well known around the entire world, even amongst non-Muslim scholars. Predictions in the Quran have come true; and its teachings are clearly for all people, all places and all times.
Surprisingly enough, the Quran itself provides us with the test of authenticity and offers challenges against itself to prove its veracity. Allah tells us in the Quran:
Haven't the unbelievers considered if this was from other than Allah, they would find within it many contradictions?
[Noble Quran 4:82]
Another amazing challenge from Allah's Book:
If you are in doubt about it, bring a chapter like it.
[Noble Quran 2:23]
And Allah challenges us with:
Bring ten chapters like it.
[Noble Quran 11:13]
Bring one chapter like it.
[Noble Quran 10:38]
No one has been able to produce a book like it, nor ten chapters like it, nor even one chapter like it. It was memorized by thousands of people during the lifetime of Muhammad (peace be upon him) and then this memorization was passed down from teacher to student for generation after generation, from mouth to ear and from one nation to another. Today every single Muslim has memorized some part of the Quran in the original Arabic language that it was revealed in over 1,400 years ago, even though most of them are not Arabs. There are over nine million (9,000,000) Muslims living on the earth today who have totally memorized the entire Quran, word for word, and can recite the entire Quran, in Arabic just as Muhammad (peace be upon him) did 14 centuries ago