Hebrews 10:14 - Matthew Poole's English Annotations on the Holy Bible

For by one offering: for here gives the reason of the precedent effect, and it is opposed to the reason of the legal offerings defect; their sacrifices multiplied could not perfect sinners, but this one doth it fully. He hath perfected for ever: Christ, God-man, the gospel High Priest, by the one offering of himself a sacrifice for sin to God his Father, and once performed by him, hath secured perfection of justification, sanctification, and blessedness, perpetually to be continued, whereby the persons interested in it are qualified and consecrated to be priests to God and his Father, (as the Aaronical priests were by the sacrifice of the ram of consecration, Exodus 29:22,24), to serve in their proportion here, but especially after the completion of it by their resurrection, they shall perfectly serve him before his throne in the holy of holiest for ever, 1 Peter 2:9 Revelation 1:6, Revelation 5:10 20:6. Them that are sanctified; the renewed souls by the Holy Ghost, such whose consciences he hath sprinkled with the blood of Jesus, and by it freed them from the guilt of sin and its punishment, and whose natures he regenerates and sanctifieth, freeing them from their evil habits, and making them inherently holiness unto the Lord, Psalms 110:3 1 Corinthians 6:11.