No doubt, the book was created for Christian families - children unfamiliar with the gospel won't understand "the disconnection" of words and visuals, and even the symbols at the end of the book won't be of help.
The hymn was written in 1995 by Stuart Townend and became an instant classic in churches around the world but its usage in a book may - or may not - trigger some copyright issues.
HOW DEEP is a metaphoric publication with symbolism that can raise plenty of questions.
What is the sin of the younger son?
What is the way for a young reader to understand that the older brother is 'us'?
How the rope disappeared in the water and suddenly appeared in the boat?
Why is the younger son (Jesus Christ) giving his treasure chest to his older brother (us)?
Is it sinful to throw an anchor in the water?
How did the younger brother claim that He was Christ?
To whom is 'God' praying when He is omnipotent?
And many more.
By the way, the illustrations are adorable. I love how the sky changed its colour accordingly...