What Is the Difference between Justification and Sanctification?
Knowing the difference between the biblical categories of justification and sanctification is key for resting in Christ and understanding our duties as God’s children. Following is a basic definition of each word:
Without understanding how they are justified in Christ, Christians may wrongly think their own works, good or bad, could keep them in or out of God’s kingdom. The Bible says that we are declared righteous in Christ—this is a legal verdict and not something that God sees inside of us:
And to the one who does not work but believes in him who justifies the ungodly, his faith is counted as righteousness. (Rom. 4:5)
Therefore, since we have been justified through faith, we have peace with God through our Lord Jesus Christ. (Rom. 5:1)
But God shows his love for us in that while we were still sinners, Christ died for us. Since, therefore, we have now been justified by his blood, much more shall we be saved by him from the wrath of God. (Rom. 5:8-9)
Christ has taken upon himself the punishment we deserve, and he has earned life for us by his perfect obedience to God’s law:
For if, because of one man's trespass, death reigned through that one man, much more will those who receive the abundance of grace and the free gift of righteousness reign in life through the one man Jesus Christ. (Rom. 5:17)
Even our faith is God’s gift to us (Eph. 2:8-9). Believers will never have to face God’s just sentence for their sins and spend eternity in hell separated from God. Think of someone in a courtroom who is guilty of a horrible crime and deserving of the severest punishment but is instead declared innocent because someone else paid the penalty for them—and even made them coheirs with him, sharing in his vast wealth! This is the joyful justification every believer has in Christ.
Not only do Christians have the benefit of being justified in Christ, they also have the benefit of sanctification. The Holy Spirit indwells every believer and is at work conforming them to the image of Christ (Rom. 8:29). According to the Heidelberg Catechism, sanctification in Christ consists of two parts:
the dying of the old self (mortification), which consists of a "heartfelt sorrow that we have offended God by our sin, and more and more to hate it and flee from it" (Q. 89);
and living unto God (vivification), which consists of "a heartfelt joy in God through Christ, and a love and delight to live according to the will of God in all good works" (Q. 90).
Christians should be diligent to grow in godliness and be confident, as the apostle Paul writes, “that he who began a good work in you will bring it to completion at the day of Jesus Christ” (Phil. 1:6).
Sadly, the Roman Catholic Church has turned around the teaching of justification and sanctification, erroneously teaching that our justification comes some day in the undetermined future, after we have completed the process of sanctification via the sacraments of Rome and purgatory. The truth is that all believers are coheirs with Christ, and sanctification is God’s gift to all his children. As the apostle John declares,
Beloved, we are God’s children now, and what we will be has not yet appeared; but we know that when he appears we shall be like him, because we shall see him as he is. (1 John 3:2)
Just as a child has the consequent duties to honor and obey his parents, so Christians have consequent duties to honor and obey their heavenly Father. Believers should expect to be recipients of the Lord’s discipline in their life when they disobey God:
It is for discipline that you have to endure. God is treating you as sons. For what son is there whom his father does not discipline? If you are left without discipline, in which all have participated, then you are illegitimate children and not sons. (Heb. 12:7-8)
Christians can rejoice, even in times of discipline, that they are God’s children and their adoption into the family of God is secure. All Christians receive the double benefit of justification and sanctification by God’s grace alone through faith alone in Christ alone.
Core Christianity: Finding Yourself in God's Story by Michael Horton
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