This islam thing all comes back to this figure Muhammad. After all, he was the perfect example to follow according to the quran. So in essence – what we find in Muhammad would be the true essence of islam, and the example to follow.
First off, let us look at the slaughter of the jewish tribe Banu Qurayzah. After a twenty-five day of blockade, the Jews gave in and surrendered with the promise of being “fairly judged”. When they laid down their weapons, the men were taken out and slaughtered in batches, and the woman and children became slaves.
Narrated Aisha, Ummul Mu’minin: No woman of Banu Qurayzah was killed except one. She was with me, talking and laughing on her back and belly (extremely), while the Messenger of Allah was killing her people with the swords. Suddenly a man called her name: Where is so-and-so? She said: I I asked: What is the matter with you? She said: I did a new act. She said: The man took her and beheaded her. She said: I will not forget that she was laughing extremely although she knew that she would be killed. Sunan Abi Dawud 2671 Book 14, Hadith 2665
As we can see here, Muhammad was personally killing people with his sword. And Muhammed had no problem with innocent children being killed. No problem whatsoever.
It is narrated by Sa’b b. Jaththama that he said (to the Holy Prophet): Messenger of Allah, we kill the children of the polytheists during the night raids. He said: They are from them.