we are discuss his prejudge about Quran in tweets .
Hang on a little bit, perhaps he was prejudiced but not against Quran. He made statements about Islam, not the Quran. He called Islam evil, not the Quran. He didn't say Quran was evil.
Put it this way, do you consider Christianity to be wrong? Or Buddhism? If you do, did you read all of the Bible? Did you read all the Buddhist books? If you didn't, then you're prejudging them in the same way as you say Dawkins is doing against Islam.
Let's go through this again:
Dawkins talked about Islam, not the Quran.
Dawkins have never read the whole Quran (but I assume he's read parts of it).
You probably have opinions about non-Islam religions.
You haven't read all books there is about each and every religion in the world, but you've probably read parts of many of them.
So in the same manner you can make a "prejudgment" regarding all other religions, or any other religion, Dawkins can make his "prejudgment" regarding all or any other religion, based on the same limited knowledge about the books.
Let's take it from yet another slightly different angle.
Religion is not the same as the religious books. A religious book can say something, but the religion might be different. Just consider that there are two or three different Islamic groups. Shi'ite and Sunni are two religions, even though there also in a sense the same, yet different. But they have the same holy book. Christianity is even worse. There are some 30,000 different denominations. Everyone interpreting their holy book a little different than the other. So, the holy book doesn't necessarily equate religion. Religion can be different than the holy book. So to express an opinion about religion, not the holy book, doesn't have to be based on what the holy book says since the religion is different that the holy book.
I know. I write very convoluted. But I hope you understand the point that Dawkins criticizing a religion is not the same as him criticizing a holy book.