Jeremiah 31:31–34 has figured prominently in the argument of the author of Hebrews for the superiority of the new covenant over the old and thus for the superiority of Christ’s priesthood over the Levitical system. Thus, it is not surprising that in today’s passage, the author of Hebrews returns to this text from Jeremiah as he concludes his argument for the perfectly effectual nature of Christ’s priestly work.
In Hebrews 10:14, we read that Jesus’ offering of Himself has perfected for all time those who are even now being sanctified. This verse is a powerful ground of assurance for us, for if we are presently growing in grace, then we can know that we will persevere to the end. The offering of Jesus guarantees the full and final salvation of everyone who is presently following Him. But the reality of this perfection, verse 15 explains, is also corroborated by the testimony of the Holy Spirit, who in Jeremiah 31:31–34 promises that in the new covenant, God will remember our sin no more. Through the prophet Jeremiah, God predicted a day when sin would no longer be counted against His people. Certainly, those who lived in Jeremiah’s old covenant era, before the coming of that day of forgiveness foreseen by the prophet, benefited from the Lord’s not holding sin against His people (see Rom. 4:6–8). Yet, as we have seen, these faithful saints who lived under the old covenant enjoyed forgiveness not by virtue of that specific covenant but by the new covenant sacrifice of Christ, applied to them in time before Jesus actually came and atoned for sin.
What is the proof that this day of forgiveness has come, that the era of God’s not counting sin against His people has been inaugurated? The fact that Jesus put an end to the sacrificial system once and for all with His death for His people. As Hebrews 10:18 argues, where forgiveness has come, there is no longer an offering for sin. By reversing the clauses of this statement, we can understand the author’s logic. Because there is no longer an offering for sin, forgiveness has fully and finally come to the people of God. Christ’s once-and-for-all sacrifice is never to be repeated because its effectual nature means that it will never need to be repeated. Thus, everything necessary to secure the pardon and everlasting life of God’s people has been achieved. Nothing more needs to be done. We need not and cannot add to the perfection of the work of Christ.