Proceeding from the prayerful dialogue between the Incarnate Son and his Eternal Father, Joseph Ratzinger shows how one can approach the mystery of the Heart of Christ only through the imitation of this prayer. To know and understand Jesus we must participate in his prayer. The prayer of Christ must be the interior life of all who are joined to him in his Body, the Church. Using the Old and New Testaments and the Church Fathers, Ratzinger shows that the ecclesial community (the Church) was born from the pierced Heart of Christ on the Cross.