By Stephen Beale, Aleteia - The Sacred Heart is among the most familiar and moving of Catholic devotional images. But its symbolism can also be strange. As we mark the Feast of the Sacred Heart early this month, here is a look at the explanation behind some of the features of the Sacred Heart. The flames. The Sacred Heart most obviously brings to mind the Passion of Christ on the cross. There is the crown of thorns, the cross, usually atop the heart, and the wound from the spear that pierced His side. But why is the Sacred Heart always shown as if it’s on fire?