Well, I find the most interesting (yet terrifying) thing about Islam its dualistic nature.
First of all, Muhammed wrote down in the Quran what Allah told him to trough his angel Djibril. Therefore, everything in the Quran is the word of Allah.
Prophet Muhammed started the Islam in Mecca, where he preached for 13 years and convinced 150 people to become Muslim. He wrote a book there, the Meccan Quran, which is rather peaceful and tolerant towards kafirs (non-Muslims).
Once he was banned from Mecca and went to Medina, he became a warlord, conquered the majority of the Arab world and subjugated 100.000 people to Islam in around 9 years. The book that he wrote there, the Meddinan Quran, is filled with hatred towards kafirs. For example, 17% of the text of the Meddinan Quran is dedicated to Jew-hatred as compared to 7% of the text of Mein Kampf, according to the count of Dr. Bill Warner.
What follows hereof is that both parts of the Quran contradict each other, but at the same time both contain the words of Allah and therefore are both true.
On the one hand, this means that I cannot hate anyone for being Muslim. Someone can call him/herself Muslim, go to a mosque, wear a headscarf, prefer the more peaceful Meccan interpretation and be one of the most amazing persons you will ever meet.
At the same time though, this means that the (Meddinan) islam also contains a lot of theological problems which are not compatible with western societies.
