A symbol of love, showing Christ's enduring love in spite of man's ingratitude. Images representing the heart alone are to be used for private devotion only. Generally the Sacred Heart is pictured as Christ, with his heart more or less exposed, sometimes held in his hands. The love of christ exhibited in his Passion is often represented as a flaming heart surrounded by a crown of thorns. Mary's heart, pierced by a sword, is usually shown encircled by roses. A number of saints have a heart as their emblem, e.g., St. Augustine, to symbolize his great love for God; St. Theresa of Avila, a pierced heart recalling the wound of the seraph that she received in ecstasy; St. Margaret Mary, because of the role she played in extending the devotion to the Sacred Heart in the modern world.