By Venerable Archbishop Fulton J. Sheen.
It seems to be a fact of human psychology that when death approaches, the human heart speaks its words of love to those whom it holds closest and dearest. There is no reason to suspect that it is otherwise in the case of the Heart of hearts.
If He spoke in a graduated order to those whom He loved most, then we may expect to find in His first three words the order of His love and affection. His first words went out to enemies: "Father, forgive them," His second to sinners: "This day thou shalt be with Me in Paradise," and His third to saints, "Woman, behold thy son." Enemies, sinners, and saints – such is the order of Divine Love and Thoughtfulness.
The congregation anxiously awaited His first word. The executioners expected Him to cry, for everyone pinned on the gibbet of the Cross had done it before Him. Seneca tells us that those who were crucified cursed the day of their birth, the executioners, their mothers, and even spat on those who looked upon them. Cicero tells us that at times it was necessary to cut out the tongues of those who were crucified, to stop their terrible blasphemies. Hence the executioners expected a cry but not the kind of cry that they heard.
The Scribes and Pharisees expected a cry, too, and they were quite sure that He who had preached "Love your enemies," and "Do good to them that hate you," would now forget that Gospel with the piercing of feet and hands. They felt that the excruciating and agonizing pains would scatter to the winds any resolution He might have taken to keep up appearances.
Everyone expected a cry, but no one with the exception of the three at the foot of the Cross, expected the cry they did hear. Like some fragrant trees which bathe in perfume the very axe which gnashes them, the great Heart on the Tree of Love poured out from its depths something less a cry than a prayer, the soft, sweet, low prayer of pardon and forgiveness. . . .
The next two words, the fourth and the fifth, betray the sufferings of the God-man on the Cross. The fourth word symbolizes the sufferings of man abandoned by God; the fifth word the sufferings of God abandoned by man. . . .When Our Blessed Lord spoke this fourth word from the Cross, darkness covered the earth.
Truly, all was darkness! He had given up His Mother and His beloved disciple, and now God seemingly abandoned Him. "Eli, Eli, lamma sabacthani?" "My God! My God! Why hast Thou forsaken Me?" It is a cry in the mysterious language of Hebrew to express the tremendous mystery of a God "abandoned" by God. The Son calls His Father, God. What a contrast with a prayer He once taught: "Our Father, Who art in Heaven!" In some strange, mysterious way His human nature seems separated from His Heavenly Father, and yet not separated, for otherwise how could He cry, "My God, My God"?
He atoned first of all for atheists, for those who on that dark midday half believed in God, as even now at night they half believe in Him. He atoned also for those who know God, but live as if they had never heard His name; for those whose hearts are like waysides on which God's love falls only to be trampled by the world; for those whose hearts are like rocks on which the seed of God's love falls only to be quickly forgotten; for those whose hearts are like thorns on which God's love descends only to be choked by the cares of the world.
It was atonement for all who have had faith and lost it; for all who once were saints and now are sinners. It was the Divine Act of Redemption for all abandonment of God, for in that moment in which He was forgotten.

[The fifth word] is the shortest of the seven cries. Although it stands in our language as two words, in the original it is one. . . .He, the God-Man, who threw the stars in their orbits and spheres into space, who "swung the earth a trinket at his wrist," from Whose finger-tips tumbled planets and worlds, who might have said, "The sea is Mine and with it the streams in a thousand valleys ...

The Seven Last Words of Christ