As'salamu Alaikum dear brother,
The Glorious Quran's current sequential order of the Noble Surahs (Chapters) is not in the order that the Surahs came in. It was the Prophet Muhammad, peace be upon him, through Angel Gabriel's help that determined where the Noble Verses go in what Surahs and what places/positions. Keep in mind that the memorization of the Holy Quran, and the recitation of the entire Holy Quran by Muslims in the Holy Month of Ramadan and throughout the year tremendously helped cement the Holy Quran and protect it from man's corruption and fabrications and alterations, as Allah Almighty Promised in the Holy Book. Visit:
http://www.answering-christianity.com/quran.htm for more details.
Today, aside from the Holy Quran's Overwhelming Scientific Miracles, Muslims have discovered ample Numerical Miracles that indeed testify to the Holy Book's Divinity and Truth. For ample details and proofs, please visit:
http://www.answering-christianity.com/ac20.htm#links.
Take care,
Osama Abdallah