The Qur'an states that it is a perfect book preserved on tablets in heaven (Surah 85:21-22). If the Qur'an is a perfect book from Allah, then there shouldn't be any contradictions in it. Of course, the Muslims will deny any contradictions exist in the Qur'an, but they do. Some of the contradictions below could be debated, but some of them are clearly contradictions.
A contradiction occurs when one statement on a subject excludes the possibility of another. The first one here is a good example. In Surah 19:67, it states that man was created out of nothing. In 15:26, man is created from clay. Since clay is something, we have a contradiction since "nothing" excludes the possibility of "clay." Both cannot be true.
All quotes from the Qur'an, unless otherwise specified, are from Yusuf Ali and can be found at the Qur'an online.
1. What was man created from, blood, clay, dust, or nothing?
1. "Created man, out of a (mere) clot of congealed blood," (96:2).
2. "We created man from sounding clay, from mud moulded into shape, (15:26).
3. "The similitude of Jesus before Allah is as that of Adam; He created him from dust, then said to him: "Be". And he was," (3:59).
4. "But does not man call to mind that We created him before out of nothing?" (19:67, Yusuf Ali). Also, 52:35).
5. "He has created man from a sperm-drop; and behold this same (man) becomes an open disputer! (16:4).
2. Is there or is there not compulsion in religion according to the Qur'an?
1. "Let there be no compulsion in religion: Truth stands out clear from Error: whoever rejects evil and believes in Allah hath grasped the most trustworthy hand-hold, that never breaks. And Allah heareth and knoweth all things," (2:256).
2. "And an announcement from Allah and His Messenger, to the people (assembled) on the day of the Great Pilgrimage,- that Allah and His Messenger dissolve (treaty) obligations with the Pagans. If then, ye repent, it were best for you; but if ye turn away, know ye that ye cannot frustrate Allah. And proclaim a grievous penalty to those who reject Faith," (9:3).
3. "But when the forbidden months are past, then fight and slay the Pagans wherever ye find them, and seize them, beleaguer them, and lie in wait for them in every stratagem (of war); but if they repent, and establish regular prayers and practice regular charity, then open the way for them: for Allah is Oft-forgiving, Most Merciful," (9:5).
4. Fight those who believe not in Allah nor the Last Day, nor hold that forbidden which hath been forbidden by Allah and His Messenger, nor acknowledge the religion of Truth, (even if they are) of the People of the Book, until they pay the Jizya with willing submission, and feel themselves subdued," (9:29).
3. The first Muslim was Muhammad? Abraham? Jacob? Moses?
1. "And I [Muhammad] am commanded to be the first of those who bow to Allah in Islam," (39:12).
2. "When Moses came to the place appointed by Us, and his Lord addressed him, He said: "O my Lord! show (Thyself) to me, that I may look upon thee." Allah said: "By no means canst thou see Me (direct); But look upon the mount; if it abide in its place, then shalt thou see Me." When his Lord manifested His glory on the Mount, He made it as dust. And Moses fell down in a swoon. When he recovered his senses he said: "Glory be to Thee! to Thee I turn in repentance, and I am the first to believe." (7:143).
3. "And this was the legacy that Abraham left to his sons, and so did Jacob; "Oh my sons! Allah hath chosen the Faith for you; then die not except in the Faith of Islam," (2:132).