We have the glorious Qur’an, preserved for 1400 years and it will be preserved until the Judgment Day, coz Allah promises that He will preserve the book.
We have, without doubt, sent down the Message; and We will assuredly guard it (from corruption). (Noble Qur’an;15:9)
and in the Qur’an itself, there’s a challenge posed by Allah unto mankind.
And if ye are in doubt as to what We have revealed from time to time to Our servant, then produce a Sura like thereunto; and call your witnesses or helpers (If there are any) besides Allah, if your (doubts) are true. But if ye cannot- and of a surety ye cannot- then fear the Fire whose fuel is men and stones,- which is prepared for those who reject Faith. (Glorious Qur’an;2:23-24)
All those people who rejected Qur’an have to do is to produce another surah just like the Qur’an, and they can proof that Muhammad s.a.w. created the Qur’an.. but for 1,400 years old, no Arab Christian can come up with a verse just like the Qur’an. They’ve tried, trust me, they have, but they made a fool out of themselves if they read it in public and claimed that their ‘verse’ has answered Qur’an’s challenge.
It’s a wonder that The Qur’an gave mankind a way to actually “debunked” itself (meaning, metaphorically, the Qur’an says “If you all can do this, then I am wrong”), but for 1,400 years nobody has been able to do it.
No Arab Christian has produced even one verse to challenge those of the Qur’an, and they speak Arabic.
But the greatest, the most greatest miracles of Muhammad s.a.w. in my humble opinion is, without performing miracles, people’s lives were changed, nations were changed (and still changing), and a tribe from the desert changed from a barbaric life style to a civilized nation. All with just the teachings of Muhammad alone.
May the peace and blessing of Allah be unto Muhammad s.a.w… the walking, talking and living Qur’an.