This book is written in the same vein and format of Webber's other ancient-future books: Christ is victor over the powers and Christians are now to live in terms of that victory. Webber takes that theme and applies it to the Christian year. In short, he argues for a return to the Christian calendar as a guide to spiritual formation.
The Christian year is thus: Advent, Christmas, Epiphany, // Lent, Triduum, Easter. The two cycles mirror each other: Anticipation (Advent, Lent), Fulfillment (Christmas, Triduum), and Proclamation (Epiphany, Easter). The Christian is to anticipate the coming of Christ/the cross of Christ; The Christian is to celebrate the fulfillment of the Story (Incarnation) and the defeat of the powers (Easter). Afterwards, the Christian is to celebrate the proclamation.
The book is not hard reading but it is unusual for most Western Christians (be they of any tradition). We are not used to thinking like this so the book forces us re-read certain parts. And it raises some questions it didn't intend.
I did enjoy the book and to my ability plan to incorporate its spiritual formation. It wasn't on the same level as his Ancient-Future Worship, but it does provide much meat for the interested one. I appreciated his discussions on Christus Victor and his warning not to let apologetics eclipse the Easter message. I have one question that I would like to see someone in this model answer: Colossians 2 warns against Jewish festivals and asceticisms. While I love the idea of festival in AFT, how do we maintain festival without falling into the warning of Colossians 2? I am willing to be convinced.