7 Give heed then to the Lord confessing; “I confess to You, O Father, Lord of heaven and earth.” I confess to You, that is, I praise You. I praise You, not I accuse myself. Now as far as the taking of very man is concerned, all is grace, singular and perfect grace. What merit had that man who is Christ, if you take away the grace, even that so pre-eminent grace, whereby it behooved that there should be One Christ, and that He whom we acknowledge should be He? Take away this grace, and what is Christ but a mere man?
What but the same as you are yourself? He took a Soul, He took a Body, He took a perfect Man; He unites him to Himself, the Lord makes one Person with the servant. What pre-eminent grace is this! Christ in heaven, Christ on earth; Christ at once both in heaven and earth; not two Christs, but the same Christ, both in heaven and earth. Christ with the Father, Christ in the Virgin's womb; Christ on the Cross, Christ succouring some souls in hell; and on the self-same day Christ in paradise with the robber who confessed.
And how did the robber attain to this blessedness, but because he held on that way, in which “He shows His salvation”? That way, from which let not your foot wander. For in that he accused himself, he praised God, and made his own life blessed. He looked in hope for this from the Lord, and said to Him, “Lord, remember me when You come into Your kingdom.” For he considered his own wicked deeds, and thought it much, if mercy should be shown him even at the last. But the Lord immediately after He had said, “Remember me”— when? “when You come into Your kingdom,” says, “Verily I say unto you, Today shall you be with Me in paradise.” Mercy offered at once, what misery deferred.
Source: Sermons on Selected Lessons of the New Testament (New Advent)