This question is understood by an appreciation of the timeless nature of Christ’s sacrifice. The Incarnation of Jesus Christ and His Passion are transcendant events which are presented before the Father from age to age. Additionally, the Incarnation is not a single, terminal event even in a temporal sense. Since Jesus Christ remains a man forever the effects of His Incarnation extend forward through history at the very least. The suffering and death of Jesus Christ are intrinsically related to His humanity and thus similarily extend in significance through the ages.
This is why the Holy Sacrifice can be re-presented before God without renewed bloodshed. Consider the Apocalypse chapter 5:
6 And between the throne and the four living creatures and among the elders, I saw a Lamb standing, as though it had been slain, with seven horns and with seven eyes, which are the seven spirits of God sent out into all the earth; 7 and he went and took the scroll from the right hand of him who was seated on the throne. 8 And when he had taken the scroll, the four living creatures and the twenty-four elders fell down before the Lamb, each holding a harp, and with golden bowls full of incense, which are the prayers of the saints; 9 and they sang a new song, saying, “Worthy art thou to take the scroll and to open its seals, for thou wast slain and by thy blood didst ransom men for God from every tribe and tongue and people and nation, 10 and hast made them a kingdom and priests to our God, and they shall reign on earth.”