Dawkins should learn the scientific definition of delusion

The diagnostic and statistical manual defines delusion as
"A false belief strongly held by a person in spite of evidence to the contrary.The belief is not ordinarily accepted by other members of the person's culture or subculture( i.e it is not an article of a religious faith)"
By definition religious belief do not come under delusions.
When a false belief is held by many persons in a culture it is called as a superstition.Religious ideas if found false can be categorized under superstition and not under delusion.
I think a scientist like dawkins should atleast study properly before choosing a title for his book.If dawkins lacks scientific knowledge about the definition of the word and it's right application how much more will be his ignorance with regard to theology ? And how much more ignorant will be he about the true God?
Belief in religion or God cannot be termed a delusion because by definition delusion excludes articles of religious
belief.
So much for the title of the book!