“When we consider it under its fundamental aspect as the cult of the love of God, rather than of the Incarnate Word, devotion to the Sacred Heart of Jesus, is as old as Christianity, even though it is only in recent centuries, that it has assumed it’s present symbolism.
“He who does not love, does not know God,” says St John, “for God is love” (1 Jn 4:8).
“And we have come to know,” he continues “and have believed, the love that God has in our behalf. God is love and he who abides in love abides in God and God in him” (1 Jn 4:16).
This cult of the love of God, particularly of the love of God-made-man, vibrates throughout the pages of the Gospel and of the writings of the Apostles, especially of St John and of St Paul.
In the works of the Fathers, there are references to the Heart of Jesus, pierced with a lance, from which flowed all the infinite graces of the Church for our redemption.
We are reminded of this in the Encyclical, Haurietis Aquas, published by Pope Pius XII in the year 1956.
But the specific cult of the love of God, as symbolized by the Heart of Jesus, was explicitly approved by the Church after Jesus Himself appeared in the year 1674 to St Margaret Mary Alacoque and showed her His Heart on fire with love for men.”
Antonio Cardinal Bacci