Justification v. Sanctification (What’s the difference?)
If you like to argue and debate the Bible, simply make the statement that no one is saved by keeping the Law of Moses or the Decalog but one is saved only by grace (unmerited favor unattainable by human effort) through faith (trusting-believing) in Jesus Christ as Lord and Mediator for our sin. The contention and confusion under girding the dissension between law keepers and those who espouse salvation by grace through faith alone is partially due to a misunderstanding of the differentiation existing between the doctrines of Justification and Sanctification.
Justification in Christianity is synonymous in many ways with righteousness or being positionally “right” with God i.e. to have a “right standing” with God the Father. Justification, relevant to our relationship with God the Father, can ONLY manifest by grace (unmerited favor you cannot earn) through faith (trusting-believing) that Jesus Christ is God who died to pay our sin-debt and that He was resurrected from the dead for our “justification” (John 3:16-18; Romans 10:9-10); therefore, “justification” can only be attained by what God has done – NOT – by what we do; Justification is a “Gift” from God the Father that cannot be earned by human effort but Jesus Christ did the WORK for sinful humanity by fulfilling the moral aspects of the Decalog and the Mosaic Law in absolute perfection for us as all of human kind is under the condemnation of sin (Romans 3:23) and it is NOT possible that mankind could fulfill the righteous requirements of the Law in perfection in order to attain righteousness and atonement necessary for entrance into the Kingdom of God subsequent to the death of the body in Time (Romans 3:20; Galatians 2:16). It is also a most valid point that to violate one-jot or one-tittle of the Law is to violate the whole Law (James 2:10; Galatians 3:10); therefore, seeing that all of mankind is under the condemnation of sin, the works of the Law could NEVER provide righteousness or atonement as the Law only defines sin and offers nothing but condemnation to the one seeking justification through same (Romans 3:20).
Sanctification, unlike Justification, is actually a work of righteousness that is accomplished through the indwelling Holy Spirit given to all who believe and trust in Jesus Christ as Lord (Ephesians 1:13-14; John 14:16; 1 John 2:27). Sanctification or a “setting apart” of the faithful for God’s purposes cannot manifest without Justification having been realized by grace through faith, alone. In other words, it is not possible to access the benefits and works of sanctification unless one has been justified by grace through faith in Jesus as Lord. Sanctification is an incremental process over the life of the believer where the indwelling Holy Spirit tutors, guides, instructs, the faithful in Jesus Christ in the ways of obedience to the Law, a Law that has been written upon our heart and infused within our mind (Hebrews 10:16) and administered by the Spirit, NOT a law etched in stone or scratched in parchment as per the Covenant of Law given the Hebrew Tribes at Sinai and through Moses.
The New Covenant is radically different and superior to the Old Covenant of Law in that the New Covenant includes mens rea or the thought life concerning culpability; the New Testament Law is administered by the indwelling Holy Spirit who guides, sanctifies, protects, supports, the faithful in Christ. In the New Covenant, in the process of sanctification, the faithful are no longer bound by an arduous set of Laws that only condemned void atonement (Romans 3:20; Galatians 3:10) but in the New Covenant, the faithful walk-in peace with God through faith in Jesus Christ (Romans 5:1) as our relationship with God the Father is secured by Covenant and the Holy Spirit daily prepares us for service in this life and in the Kingdom of God, a glorious servitude that will manifest subsequent to the death of our body in Time (Revelation 1:6).
Justification can only manifest by grace through faith in Jesus as Lord and this is NOT of our own doing but it is a Gift provided us by God the Father and earned for us by Jesus’ faithfulness in fulfilling the Law on our behalf and faithfully giving Himself as a blood sacrifice for our sin and the Father has promised via a Covenant of Grace (Matthew 26:28) to impute the perfection, the righteousness, of Jesus into and over the life of the one who believes that Jesus is God who died to pay our sin-debt (2 Corinthians 5:21).
Sanctification, on the other hand, cannot manifest until Justification has become a reality in one’s life. It is the process of Sanctification and our obedience to the Holy Spirit that affirms and validates our confession, our Justification, as authentic and the one who is Justified will be Sanctified and Glorified by the Spirit as the Spirit is ONLY given to the one who is Justified by grace through faith, alone.