Does one need proof to come to a certain belief? We can look at the signs in nature and find out what happened to certain people in the past, such as Noah and Paul. With the Book of Books, Allah has provided the world with His Interpretative Word.
One may wonder in which or what kind of god people want to believe. It is striking that many people like to have a certain form of mystery around their deity and therefore do not choose the God Who pours clear wine and sends very reliable Words to earth.
Daily lots of people consume bread, but they should know there is even better spiritual bread that can bring us closer to the Divine Creator.