It’s a book openly written to un-convert to the converted, and for the same reason can be very controversial and some people even considered it as offensive (e.g. in the first chapter it explains the sins of the God of the Old Testament).
It provides evidence on why Natural Selection is a better theory than the so called theory of the Intelligent Design (The God hypothesis).
The book defends the children’s right to don’t be labeled as adherents of any religion only for that fact that their parents are. Children are free individuals and must think for them selves.
It provides the following scale to measure the belief of the persons:
1.00: Strong theist. 100 percent possibility of God. In the words of C.G. Jung, ‘I do not believe, I know.’
2.00: Very high probability but short of 100 per cent. De facto theist. ‘I cannot know for certain, but I strongly believe in God and live my life on the assumption that he is there
3.00: Higher than 50 per cent but not very high. Technically agnostic but leaning towards theism. ‘I am very uncertain, but I am inclined to believe in God.’
4.00: Exactly 50 per cent. Completely impartial agnostic. ‘God’s existence and non-existence are exactly equiprobable.’
5.00: Lower than 50 per cent but not very low. Technically agnostic but leaning towards atheism. ‘I don’t know whether God exists but I’m inclined to be sceptical.’
6.00: Very low probability, but short of zero. De facto atheist. ‘I cannot know for certain but I think God is very improbable, and I live my life on the assumption that he is not there.’
7:00: Strong atheist. ‘I know there is no God, with the same conviction as Jung ‘knows’ there is one.’
The book explains that non-belivers (atheist) are happy, moral, balanced and healty persons (being an atheist is being considered as bad thing for many religious people, specialy in USA). And encourages the atheist to be prod of it.