Reminder no. 1: God has a human nature
Today's feast is devoted to the doctrine of the hypostatic union -- which is a fancy way of saying that two natures, human and divine, are united in the one divine Person of Christ.
When our worship focuses on God's divine nature, we worship God Himself. When our worship focuses on God's human nature, we worship God Himself. And when we worship even a piece of His human nature, muscles or blood or eyelids, we worship God Himself. Not everyone agrees on that -- the Jansenists sure didn't -- but it's true.
Reminder no. 2: God loves you
So why commemorate the Sacred Heart and not the Sacred Elbows, for instance? Because the heart symbolizes love itself. The human heart of Jesus is the symbol of His infinite love -- for the Father, for all mankind, and particularly for you.
Father, we have wounded the heart of Jesus your Son, but He brings us forgiveness and grace. Help us to prove our grateful love and make amends for our sins. Amen.