The fundamental theme of this work is that prayer, like everything else that comes to man through God's self-revelation in Christ (such as grace; faith, hope and love; or the realtionship between Christ and the Church), is ultimately rooted in God himself and in his triune exchange of life.
Beyond all purely creaturely motives and needs, Christian prayer is a participation in the inner life of the Trinity, which is revealed, prepared and accomplished in the world by Jesus Christ our Lord. By him it is made available for us to take part in.
This book is much more than a manual on how to pray. It gives an in-depth description of prayer: first the prayer of the Trinity, then the prayer of Christ, then of the Blessed Virgin, and finally that of all Christians. In particular, the section on the prayer of Mary is a masterful description of the various stages of growing in prayer. Mary is the perfect model because of her intimate association with her Son.