Is not He (better than your so-called gods) Who originates creation, and shall thereafter repeat it, and Who provides for you from heaven and earth? Is there any ilah(god) with Allah(God)? Say, "Bring forth your proofs, if you are truthful." (Al Quran : 27:64)
In light of the above verse from the Qur'an, it is only fair that non-muslims get to ask the same to the muslims - which is 'bring your proof, if Islam is the Truth'.
For any religion to claim that they have a Holy book which is from God(via one of God's messengers) at the present time,
they need to prove the following :
1.
The message in that Holy Book has indeed been preserved from the time of the messenger till current time (In other words, historical authenticity of the preservation of the text. That way we know for sure that whatever the messenger claimed to be God's words when we was present, is still with us in its original form.)
2.
The message in that book is indeed from God (In other words, it couldn't be possibly from a human being.)
Evidences for both of the above together will confirm that the message in that book is indeed from God (the Creator of the Heavens and the Earth) and it had been preserved accurately throughout history, so everything in it is from GOD and True. Once you prove that,there's no reason why any reasonable person wouldn't accept that book as God's True Message - whether one chooses to follow it is a whole different story.
So let me start with some basics to explain what will constitute proving the Truth of Islam.
Preservation of the Qur'an - proves #1 above
Scientific Facts in the Qur'an - proves #2 above
Historical Facts in the Qur'an - proves #2 above
Prophecies in the Qur'an/Prophet Muhammad(PBUH)'s Sayings - proves #2 above
Literary Miracle of the Qur'an in Arabic - proves #2 above
Since this is a vast topic and covers a lot of things,
if you prefer to watch videos, there is a great video in YouTube that covers the evidences for the Truth of Islam. You can choose to watch just the scientific facts and not the others or all. They are all in this playlist :
The Proof That Islam Is The Truth - Abdur-Raheem Green - YouTube
Otherwise, if you prefer reading over watching ... carry on ;-)
Preservation of the Qur'an
The Holy Qur'an still exists in its original form in the original language. It has been preserved in writing as well as through memorization for centuries. Yes, millions of people around the world have memorized the Qur'an in Arabic cover to cover, letter for letter. This in and of itself is a miracle given majority of
those memorizers would not understand a word of Arabic. How many other books do you know that can claim that ?
For more information on the way the Qur'an was preserved, please visit:
Proof of The Preservation of the Quran
Scientific Facts in the Qur'an
Historical Facts in the Qur'an
Prophecies in the Qur'an/Prophet Muhammad(PBUH)'s Sayings
For the Scientific and the Historical Facts as well as the Prophecies please visit :
Islam: Creation, Science, Miracle, Quran & Religion. Book Exploring The Qur'an.
The linked YouTube video on this is probably better since it is divided in different sections.
Literary Miracle of the Qur'an in Arabic
It is really hard to understand this one, without knowing Arabic. However, the following should suffice for the purpose of our discussion.
"If you have doubts about what We have sent down to Our servant, produce another chapter equal to it, and call your witnesses, besides Allah, if you are telling the truth. (Qur'an, 2:23)
One of the reasons that the Qur'an is described as miraculous stems from the fact that, as emphasized in the verses above, nothing like it can ever be written by human endeavour: The greater the scale of that impossibility, the greater the size of the miracle which we see before our very eyes. Therefore, the fact that the style of the Qur'an has been incapable of imitation by even one out of the billions of people down the centuries is one of the proofs of its miraculous nature. In his book, The Construction of the Bible and the Qur'an, F. F. Arbuthnot makes the following comment about the Qur'an:
From the literary point of view, the Koran is regarded as a specimen of the purest Arabic, written on half poetry and half prose. It has been said that in some cases grammarians have adopted their rules to agree with certain phrases and expressions used in it, and that though several attempts have been made to produce a work equal to it as far elegant writing is concerned, none has as yet succeeded." [Taken from
http://www.ilmkidunya.com/student_articles/quran-miracle-of-miracles-387.aspx]
Finally for the ultimate skeptics, what are the chances that all of the above just happened as a co-incidence or by chance. To see the probability, read the following article :
Islamic Research Foundation - Athiest Proof of Allah(swt)
Peace.