Today throughout the Church is the feast of the Sacred Heart of Jesus. For a thorough treatment of the devotion you can read the article on it at the Catholic Encyclopedia, or for fully authoritative teaching on the Sacred Heart you can read the more recent 1956 encyclical Haurietis Aquas from the hand of Pope Pius XII.
Rather than duplicate what these two sources explain and teach, we might just focus on an essential truth of this devotion. The Sacred Heart of Jesus is very much his human heart. It is not so much that we worship the flesh and blood of his physical heart in itself, but rather what it symbolizes. In general use, we refer to the heart as the centre of our feeling and emotion, our inmost core, the place where we encounter God, and from which springs what love we can show to Him and to others. Much as when our physical heart ceases to function our body dies, so too this metaphorical (yet real!) heart is the life of our spirit. Jesus Christ, as a man as well as God, had such a human heart, both literally and metaphorically.
Thus, in a sense, the devotion to the Sacred Heart is a bold and audacious one. In adoring Jesus’ Sacred Heart we are adoring his humanity. Or to put it less disturbingly, we are adoring his Incarnation. For this real and metaphorical human heart of Jesus is ennobled and elevated (and we might even say completed) by its intimate and indivisible union with his divine nature, and thus with the most intimate life of God. In Jesus’ heart humanity and divinity encounter each other for us and for our salvation.
Jesus’ love for us, consummated in his self-sacrifice on the Cross (for no greater love has anyone than to lay down one’s life for one’s friends), springs from his Sacred yet human heart. At the same time, since it is the heart also of the incarnate Second Person of the Trinity, that self-giving love is transformed into something with divine power and effect. That is why Jesus’ death is not just the simple death of another man. His is a death that reveals a love that is totally other-centred: paradoxically, both for us and at the same time for the Father. For Jesus’ love for the Father cannot be separated from his love for humanity, as we see most clearly in John 17, where Christ prays to the Father that “all mine are thine, and thine are mine, and I am glorified in them” (v.10). Christ’s love for the Father reaches its zenith when he obeys the Father’s will that he should die for sinful humanity; Christ’s love for sinful humanity reaches its zenith by the very same obedience to the Father’s will.
So in Jesus’ Sacred Heart our Lord’s human love for us, and the suffering and anguish it entailed, meets, is accepted by and united with the divine love of God, the heart of the great Easter event of our salvation. In Jesus’ Sacred Heart the price of sin is paid and accepted. In his Heart, justice and mercy embrace and are satisfied.
