But Christ was also the most sorrowful of men. He saw, as no one else could, the full, profound horror of sin, its ugliness, foulness, loathsomeness. He saw the constant inclinations to sin in men, even in the best men. He saw the dominion of the devil over men, and the constant readiness of men to accept that dominion and to reject Christ. "All seek the things that are their own, not the things that are Christ's." (Phil. II.21.) Particularly in Gethsemane, He allowed this vision of sin to fill His Heart with bitter anguish. And for Him, this ugliness of sin was not the general, abstract thing that it must remain for us, for He saw all sin, all sins, in all their hideous details; He saw each of those sins steaming up as an unholy vapour against the face of His Father; He saw them descending upon Himself as blows, insults, scourges, nails, agony inflicted upon His own Person. He used His divine power and the powers given to His human nature to prevent this flood of ugliness, shame and insult from inundating and crushing His human heart during most of His life (as a thoughtful man will conceal a toothache so as not to cause embarrassment to his friends). But from the moment of entry into the garden to the last sigh on the cross, He allowed that flood of iniquity to work its full cruel power over His tender Heart.
By becoming man, He placed man in an altogether new relation to God, because man now became able to rejoice and to gladden the Heart of God. The blows of the lashes, and particularly the insensitive cruelty of mind from which the flogging sprang, these things had the power to hurt God Himself. And that hurt was inflicted, not only two thousand years ago by men now dead; it is inflicted by you and me today. We still have the power to rejoice and to sadden the Heart of God, because His Passion goes on to the end of time—though how, we know not.
So Christ asks us, in reparation for our past faults and neglect and coldness, to join Him in His sorrows, to stop the insensitive cruelty we have shown Him; He asks us to return love for love; He asks us to take our stand not with the executioners, torturers and evil judges, but with Mary and John, to join Him in sorrow at the cross; this also we can do, for the Passion goes on to the end of time. He asks us now to share in the profound sorrows of His Heart that we may one day share fully in His joys, or rather in His joy, the mysterious joy of living in the bosom of the Triune God.
We have here a simple way of summing up the essentials of devotion to the Sacred Heart. The essence of it is to give every possible joy to the Heart of the Man-God, and to avoid, as far as we can, giving Him pain; to share as fully as we can in His sorrows that we may share in His joy. To live by this effort is to join constantly, and ever more and more intimately, in the joys, the sorrows, the aspirations of the Heart of Christ. Now the one force that enables us to enter into another person's joys and sorrows is love. Love enables us to know others, to know their mind and heart, with a kind of knowledge that can be acquired by no other way than love. Without in any way belittling the formal study of theology, we can say that no knowledge acquired of Christ through books can compare with the knowledge that comes through faithful, persevering love; and this is true even of those who, on account of their duties, are obliged to obtain knowledge of Him through books. Love unlocks the heart, not only of him who loves but also of the beloved, and brings one into the inner recesses of the beloved's mind and heart. This is the meaning of the saying attributed to Aquinas that he had learnt more from his crucifix than from his books.
God the Son gave Himself a human heart that He might as a man enter fully into the human emotions of joy and sorrow; He gave Himself a perfect heart that He might experience all that sorrow and joy perfectly. He gives us that perfect heart that we may be able to feel all He feels with His perfect heart. In return, He asks that we give Him our heart, not that He would take anything away from us, but that He may fill our heart, as He filled His own—fill it first with sorrow that He may later fill it to the very brim with joy. In proportion as we give Him our heart, He gives us the thoughts and feelings of His heart; His heart and ours become one, and Christ and the Christian become one in perfect love. So we can arrive at the highest happiness possible on this earth—a truly personal appreciation of the personal love which the Heart of Christ has for each man.