The New Covenant in Hebrews 10
In this final chapter of Hebrews focused on the new covenant, the author begins with the important theme of perfection. The law could not make “perfect” (Heb 10:1). The law required repeated sacrifices because it did not accomplish what it actually claimed to do (though God treated it as if it was effective). It is in the offering of Christ that the covenant community is sanctified (Heb 10:10). But the covenant community is also “being sanctified” and this is true for all “He has perfected” (Heb 10:14). But what is this perfection? Is it a permanence of justification? Or is it more properly the establishment of a kingdom of priests (Exo 19:6; 1 Pet 2:9)? Both options explain why the church can “enter the holy places” for they have become legitimate priests of God through the “consecration” of Jesus Christ. He as a High Priest is able to anoint priests. As Aaron consecrated his sons, so Jesus Christ has consecrated the church.
This is the difficult portion of Hebrews. For it is at this point that the author presents his most stern warning. For "if we go on sinning deliberately" after the covenant sacrifice there remains no sacrifice. This covenant cannot be rejected in favor of another (Heb 10:26)! Instead, there should be the knowledge of fire for the enemies of God (Heb 10:27). This simple imagery points to two important Biblical accounts. The first is less direct and applies to the baptism promised by John the baptizer (Matt 3:11; etc.). For in Christ there is baptism with the Holy Spirit and fire. Far from being simple synonyms (as Calvin taught), this baptism by fire is the judgment upon the covenant people of God who reject Christ (Matt 3:12; 1 Pet 4:17). Jesus Christ brought a sprinkling by the Holy Spirit (Heb 9:14) but also a judgment of fire.
The second Biblical account is more directly applicable to the context. In fact it may dictate the interpretation of this important passage. That Biblical account is the offering of profane fir by Nadab and Abihu,
1 Now Nadab and Abihu, the sons of Aaron, each took his censer and put fire in it and laid incense on it and offered unauthorized fire before the Lord, which he had not commanded them. 2 And fire came out from before the Lord and consumed them, and they died before the Lord. 3 Then Moses said to Aaron, “This is what the Lord has said: ‘Among those who are near me I will be sanctified, and before all the people I will be glorified.’” And Aaron held his peace. – Leviticus 10:1-3
Moses consecrated Aaron and his sons through washing of water (Lev 8:5-6, 10-13). The blood of the sacrifice that cleansed them was placed upon them as a mark of their priesthood (Lev 8:22-24). The end result of the washing with water and blood is the “perfection” of Aaron and his sons (Lev 8:30, 33). To prove the validity of this new priesthood, Aaron received the Lord’s favor through fire consuming his sacrifice (Lev 10:22-24). And in contrast to the telling new “fire” of Aaron, these newly consecrated priests (Aaron’s son) were destroyed by fire (Lev 10:3). Having broken the covenant sacrifice and “profaned the blood of the covenant” they were judged (Heb 10:29).
This warning passage lays out the terms of this passage. The new covenant community was in a greater covenant. It is a better covenant with better promises that made every member a priest able to enter into the “holy places” (Heb 10:19). It was purchased with the blood from the “Son of God” by which the church was sanctified and “perfected/consecrated” (Heb 10:14, 29). And yet, for those who turn in their rebellion against the Holy Spirit they will find Him an enemy (Isa 63:10) and should expect a fiery judgment.
The only way this final warning makes sense is to accept the basic themes of the book. Jesus Christ brings about a new Levitical consecration. This consecration is the initiation of the new covenant. This new covenant promises great things including the better rest. This consecration is applied to a covenant community that can still fall away in the wilderness by profaning the holiness of God.