Justification and sanctification are both essential to God's purposes regarding salvation. However, most are far more familiar with justification.
Some believe that justification preserves one's salvation through to the resurrection. This cannot possibly be so, though, because that would mean that justification is salvation. In Hebrews 6:1, this same author writes, "Let us go on to perfection." At the time one is justified, the perfection or maturity of which he writes is still future.
Sanctification is the inward spiritual transformation that Jesus Christ, as our High Priest, works in a convert by His Holy Spirit following justification. I Corinthians 1:30 informs us that Christ is not only our righteousness but also our sanctification. Hebrews 2:11 names Him as "He who sanctifies," and in the same verse, His brethren are called "those who are being sanctified." During Jesus' prayer in John 17:19, He says, "And for their sakes I sanctify Myself, that they also [the converts] may be sanctified by the truth." Ephesians 5:26-27 adds, ". . . that He might sanctify and cleanse her with the washing of water by the word, that He might present her to Himself a glorious church, not having spot or wrinkle or any such thing, but that she should be holy and without blemish."
If words mean anything, these verses—and there are many more—teach us that Jesus Christ undertakes the sanctification of His brothers and sisters no less than He does their justification.
Hebrews 10:14 is apt to be misunderstood. Perhaps this illustration may help: Imagine an observer, who, looking to his left, sees a perfect work—Christ's sacrificial offering for our justification—already completed in the past. On his right, he sees an ongoing continuous process—our sanctification—stretching off into the future. The author of Hebrews is showing that Christ's one offering is so efficacious that nothing can be added to it. It will provide a solid foundation for the continuing process of godly character growth to holiness for all mankind for all time.
In the Old Testament, the words translated as "sanctify" and "holy" are derived from the same Hebrew root, and in the New Testament, they come from the same Greek root. In both languages, they are used in essentially the same way, meaning "to be made or declared clean or purified." Because of the sense of cleanliness, both imply being different from others of their kind that are not holy, and thus they are separated or set apart from what is common. One author suggests that the cleanliness of something holy makes it "a cut above."
Justification is essentially a legal operation on God's part by accounting Christ's righteousness to us because of faith on our part. Romans 4:1-5 confirms this:
What then shall we say that Abraham our father has found according to the flesh? For if Abraham was justified by works, he has something of which to boast, but not before God. For what does the Scripture say? "Abraham believed God, and it was accounted to him for righteousness." Now to him who works, the wages are not counted as grace but as debt. But to him who does not work but believes on Him who justifies the ungodly, his faith is accounted for righteousness.
No works on our part are acceptable for justification. There is no way a sinner can "make up" for his sins. By contrast, we are deeply involved in the sanctification process, where works are very important. Ephesians 2:10 from the Amplified Bible clearly states our responsibility following conversion:
For we are God's [own] handiwork (His workmanship), recreated in Christ Jesus, [born anew] that we may do those good works which God predestined (planned beforehand) for us [taking paths which He prepared ahead of time], that we should walk in them [living the good life which He prearranged and made ready for us to live].
After being justified, we are required to live obediently, to submit to God in faith, glorifying God by overcoming Satan, the world, and human nature. Sanctification is normally the longest and most difficult aspect of salvation. Real challenges, sometimes very difficult ones, abound within it if we are to remain faithful to God, the New Covenant, and His purpose.
John W. Ritenbaugh
Where Is God's True Church Today?