Christ offered Himself once at the end to accomplish that which was mediated to His People from the “foundation of the world”. The sacrifices performed from the foundation of the world were sufficient and efficacious for the elect because of the one typified sacrifice at “the end of the ages”. We read that if the one sacrifice were not sufficient even for the saints of old, Christ would have had to have been sacrificed over and over from the beginning. Why? Because His saints of old were saved by the one redemptive work of Christ, just as are we. The true Sacrifice, though coming at the end of the ages, was by faith appropriated by the saints of old through the God ordained system of sacrifices in the Old Covenant.
For the life of the flesh is in the blood, and I have given it for you on the altar to make atonement for your souls, for it is the blood that makes atonement by the life. (Leviticus 17:11)
All orthodox believers understand that the sacrifices of the Old Testament were typical of the one vicarious, life for life, substitutionary sacrifice of our Lord Jesus Christ. Christ is called the Lamb of God that takes away the sins of the world (Jn. 1:29), the Pascal Lamb (1 Cor. 5:7), the Sacrifice of Atonement (1 Jn. 2:2), and He who “gave Himself up for us, an offering of sacrifice to God for an odor of a sweet smell” (Eph. 5:2). This should not be disputed. But how were these ancient animal sacrifices “sufficient and efficacious, through the operation of the Spirit, to instruct and build up the elect in faith in the promised Messiah, by whom they had full remission of sins, and eternal salvation” (Westminster Confession of Faith, CH. 8.6)? A short perusal of the Book of Hebrews will help make this plain.
To begin with, sacrifices were offered to God by the very first generation after the fall of Adam and Eve. Both Abel and Cain brought sacrifices to God from their labors. Cain’s was rejected, but Abel’s accepted:
By faith Abel offered to God a more acceptable sacrifice than Cain, through which he was commended as righteous, God commending him by accepting his gifts. (Hebrews 11:4)
This example of faith-righteousness leads off the “hall of faith” recorded in Hebrews 11. We see that from the very beginning, sacrifices were offered, and when in faith, were efficacious unto righteousness, which we know is had only through Christ.
Noah offered such sacrifices to God when he left the Ark: “and when the Lord smelled the pleasing aroma, the Lord said in his heart, ‘I will never again curse the ground because of man’” (Gen. 8:21). Abraham and all the Patriarchs also offered such sacrifices, acceptable to God by faith. It was thereby that they “called upon the name of YHWH” (Gen. 26:25), the Covenant Name of God.
But, of course, the most careful, detailed, and explanatory presentation of the system of Old Testament sacrifice was given to God’s People after the Exodus from Egypt, and it is with these that we see explicit interaction from the author of Hebrews. To begin with, we read that the whole Temple and system of sacrifices in the Old Covenant were carefully constructed and done after the pattern of the heavenly Temple and the sacrifices patterned after one eternal sacrifice, Jesus Christ:
They [the OT priests] serve a copy and shadow of the heavenly things. For when Moses was about to erect the tent, he was instructed by God, saying, “See that you make everything according to the pattern that was shown you on the mountain.” (Hebrews 8:5)
Even the first covenant had regulations for worship and an earthly place of holiness[…]. But when Christ appeared as a high priest of the good things that have come, then through the greater and more perfect tent (not made with hands, that is, not of this creation) he entered once for all into the holy places, not by means of the blood of goats and calves but by means of his own blood, thus securing an eternal redemption. (Hebrews 9:1, 11-12)
The whole Old Covenant cultus of temple and sacrifice was in no sense arbitrary, but intended to correlate to and picture the heavenly reality behind them; the whole typical system was methodically patterned after that which it typified, and that which the saints of old participated in by faith. Christ was indeed the substance of this whole system, and these sacrifices were not merely pictures for the saints of old. Rather, those under the Old Covenant were redeemed in their day by the blood of the perfect effectual sacrifice that was pictured, just as are we:
Therefore he is the mediator of a new covenant, so that those who are called may receive the promised eternal inheritance, since a death has occurred that redeems them from the transgressions committed under the first covenant. (Hebrews 9:15)
This is because Christ was the Testator of a testament (or “will”) that secured to them the promised inheritance. This testament, or will, while already legally in force in the Old Testament yet required the death of the testator, “for where a will is involved, the death of the one who made it must be established” (Heb. 9:16). The blood of the testator was required for the covenanted inheritance to be dispensed. This is why all the blood in the Old Covenant system:
Therefore not even the first covenant was inaugurated without blood. For when every commandment of the law had been declared by Moses to all the people, he took the blood of calves and goats, with water and scarlet wool and hyssop, and sprinkled both the book itself and all the people, saying, “This is the blood of the covenant that God commanded for you.” And in the same way he sprinkled with the blood both the tent and all the vessels used in worship. Indeed, under the law almost everything is purified with blood, and without the shedding of blood there is no forgiveness of sins. (Hebrews 9:18-22)
Thus Christ, the testator of the will, Himself the true Priest and true Sacrifice, came to accomplish, even for the Old Covenant people, what was being done day after day, year after year, under the types and shadows of the Old administration of His once and for all saving work: