ALLAH supported His last Prophet MUHAMMAD (S.A.W.W) with many miracles to prove that He is a true Prophet sent by Him. Also, ALLAH supported His last book, the Holy Quran with many miracle to prove that Quran is revealed by Him, and not by a human being
The Quran was revealed to Prophet MUHAMMAD (S.A.W.W) through the Angel Gabriel. It was memorized by MUHAMMAD (S.A.W.W) , who then dictated it to his Companions/Shabah (R.A). They memorized it, wrote it and reviewed it with the Prophet MUHAMMAD (S.A.W.W) . And from this day, there has always been a huge number of Muslims who have memorized all of the Quran, letter by letter. Not even a single letter of Quran has been changed over the lifespan of 14 centuries.
The Quran which was revealed over 14 centuries ago also mentioned many facts discovered recently or proven by scientists. This proves that Quran must be the Book revealed by ALLAH to MUHAMMAD (S.A.W.W) , and not by any other human being. It is impossible that a simple human being, fourteen hundred years ago, would have known these facts which the scientist are discovering or proving now a day with the help of advanced equipment and sophisticated scientific methods.
Some of these miracles of Quran are listed :
The Quran on Human Embryonic Development
The Quran on Mountains
The Quran on the Origin of the Universe
The Quran on the Cerebrum
The Quran on Seas and Rivers
The Quran on Fresh and Salty water
The Quran on Deeps Seas and Internal Waves
The Quran on Clouds
The Quranic Verses on Roman and Persian War