For the heart is an expression for the human (passions)—i.e., not only man’s passions but also the “passion” of being human. …the heart is the epitome of the passions, without which there could have been no Passion on the part of the Son. The encyclical cites Justin, Basil, Chrysostom, Ambrose, Jerome, Augustine, John Damascene, exhibiting different variations of the same theme, which it sees as common ground in patristic Christology: … passionum nostrarum particeps factus est (he has come to share in our “passions”).

Joseph Ratzinger, Behold The Pierced One: An Approach to a Spiritual Christology, trans. Graham Harrison (San Francisco: Ignatius Press, 1986), pages 56–57.

(My Notes: Pope Benedict is commenting on the papal encyclical Haurietis Aquas “You will draw water”. In a similar way that we may have a passion for a sports team or a specific movie or a particular wine, Jesus has a passion for us, His brothers and sisters. Jesus is passionately in love with us, His heart is on fire with love for us. His love is so great for us that he came to earth and was born as a child and lived among us, taught and healed us, and then even died a brutal death on the cross for us. A Roman solder pierced His Sacred Heart with a spear. Can we not return some measure of passionate love back to Jesus?