Aquinas on the Death of Christ:
1. To make our redemption complete. For, although any suffering of Christ had an infinite value, because of its union with His divinity, it was not by no matter which of His sufferings that the redemption of mankind was made complete, but only by His death. So the Holy Spirit declared speaking through the mouth of Caiaphas, It is expedient for you that one man shall die for the people (John xi. 50). Whence St. Augustine says, “Let us stand in wonder, rejoice, be glad, love, praise, and adore since it is by the death of our Redeemer, that we have been called from death to life, from exile to our own land, from mourning to joy.”
2. To increase our faith, our hope and our charity. With regard to faith the Psalm says (Ps. cxl. 10), I am alone until I pass from this world, that is, to the Father. When I shall have passed to the Father, then shall I be multiplied. Unless the grain of wheat falling into the ground die itself remaineth alone (John xii. 24).
As to the increase of hope St, Paul writes, He that spared not even his own Son, but delivered him up for us all, how hath he not also, with him, given us all things? (Rom. viii. 32). God cannot deny us this, for to give us all things is less than to give His own Son to death for us. St. Bernard says, “Who is not carried away to hope and confidence in prayer, when he looks on the crucifix and sees how Our Lord hangs there, the head bent as though to kiss, the arms outstretched in an embrace, the hands pierced to give, the side opened to love, the feet nailed to remain with us.”
Come, my dove, in the clefts of the rock (Cant. ii. 14). It is in the wounds of Christ the Church builds its nest and waits, for it is in the Passion of Our Lord that she places her hope of salvation, and thereby trusts to be protected from the craft of the falcon, that is, of the devil.
With regard to the increase of charity, Holy Scripture says, At noon he burneth the earth (Ecclus. xliii. 3), that is to say, in the fervour of His Passion He burns up all mankind with His love. So St. Bernard says, “The chalice thou didst drink, O good Jesus, maketh thee lovable above all things.” The work of our redemption easily, brushing aside all hindrances, calls out in return the whole of our love. This it is which more gently draws out our devotion, builds it up more straightly, guards it more closely, and fires it with greater ardour.