The term original sin refers to Adam’s sin of disobedience in eating from the tree of knowledge of good and evil and its effects upon the rest of the human race. Original sin can be defined as the moral corruption we possess as a consequence of Adam’s sin, resulting in a sinful disposition manifesting itself in habitually sinful behavior. The doctrine of original sin focuses particularly on its effect on our internal nature and our standing before God. There are three main views that deal with that effect: Pelagianism: This view says that Adam’s sin had no effect upon the souls of his descendants other than that he provided a sinful example. Adam’s example has influenced those who followed him to also sin. But, according to this view, man has the ability to stop sinning if he simply chooses to. Pelagianism runs contrary to a number of passages that indicate man is hopelessly enslaved by his sins (apart from God’s intervention) and that his good works are “dead” or worthless in meriting God’s favor (Ephesians 2:1–2; Matthew 15:18–19; Romans 7:23; Hebrews 6:1; 9:14).
Arminianism: Arminians believe Adam’s original sin has resulted in the rest of mankind inheriting a corrupt, sinful nature, which causes us to sin in the same way that a cat’s nature causes it to meow—it comes naturally. According to this view, man cannot stop sinning on his own; God’s supernatural, enabling grace, called prevenient grace, in conjunction with the gospel, allows that person to choose to exercise faith in Christ. The teaching of prevenient grace is not explicitly found in Scripture. Calvinism: The Calvinistic doctrine of original sin states that Adam’s sin has resulted not only in our having a sin nature, but also in our incurring guilt before God for which we deserve punishment. Being conceived with original sin upon us (Psalm 51:5) results in our inheriting a sin nature so wicked that Jeremiah 17:9 describes the human heart as “deceitful above all things and beyond cure.” Not only was Adam found guilty because he sinned, but his sin was imputed to us, making us guilty and deserving of his punishment (death) as well (Romans 5:12, 19). There are two views as to why Adam’s sin should be imputed to us. The first view states that the human race was within Adam in seed form; thus, when Adam sinned, we sinned in him. This is similar to the biblical teaching that Levi (a descendant of Abraham) paid tithes to Melchizedek in Abraham (Genesis 14:20; Hebrews 7:4–9), even though Levi was not born until hundreds of years later. The other main view is that Adam served as our representative, and so, when he sinned, we were found guilty as well. Both the Arminian and Calvinistic views teach original sin and see individuals as unable to overcome sin apart from the power of the Holy Spirit. Most all Calvinists also teach imputed sin; some Arminians deny imputation of sin, and others believe that Christ’s death has negated the effects of imputation.
The fact of original sin means that we cannot please God on our own. No matter how many “good deeds” we do, we still commit sin, and we still have the problem of a corrupt nature within. We must have Christ; we must be born again (John 3:3). God deals with the effects of original sin in our hearts through the process of sanctification. Sanctification is God’s will for us (1 Thessalonians 4:3). The word sanctification is related to the word saint; both words have to do with holiness. To “sanctify” something is to set it apart for special use; to “sanctify” a person is to make him holy. Jesus had a lot to say about sanctification in John 17. “They are not of the world, even as I am not of the world. Sanctify them through thy truth: thy word is truth.” John 17:16–17 In Christian theology, sanctification is a state of separation unto God; all believers enter into this state when they are born of God: “But of him are ye in Christ Jesus, who of God is made unto us wisdom, and righteousness, and sanctification, and redemption:” 1 Corinthians 1:30
The sanctification mentioned in this verse is a once-for-ever separation of believers unto God. It is a work God performs, an intricate part of our salvation and our connection with Christ (Hebrews 10:10). This state of holiness before God is sometimes referred to as “positional” sanctification; it is the same as justification. While we are positionally holy (“set free from every sin” by the blood of Christ, Acts 13:39), we know that we still sin (1 John 1:10). That’s why the Bible also refers to sanctification as a practical experience of our separation unto God. “Progressive” or “experiential” sanctification, as it is sometimes called, is the effect of obedience to the Word of God in one’s life. It is the same as growing in the Lord (2 Peter 3:18) or spiritual maturity. God started the work of making us like Christ, and He is continuing it (Philippians 1:6). This type of sanctification is to be pursued by the believer earnestly (1 Peter 1:15; Hebrews 12:14) and is effected by the application of the Word (John 17:17). Progressive sanctification has in view the setting apart of believers for the purpose for which they are sent into the world: “As thou hast sent me into the world, even so have I also sent them into the world. And for their sakes I sanctify myself, that they also might be sanctified through the truth.” John 17:18–19
That Jesus set Himself apart for God’s purpose is both the basis and the condition of believers being set apart (John 10:36). We are sanctified and sent because Jesus was. The Lord’s sanctification is the pattern of and power for our own. The sending and the sanctifying are inseparable. On this account believers are called “saints” (hagioi in the Greek), or “sanctified ones.” Prior to salvation, ones behavior bore witness to ones standing in the world in separation from God, but now ones behavior should bear witness to ones standing before God in separation from the world. Little by little, every day, “them that are sanctified.” (Hebrews 10:14) are becoming more like Christ. There is a third sense in which the word sanctification is used in Scripture—a “complete” or “ultimate” sanctification. This is the same as glorification. “And the very God of peace sanctify you wholly; and I pray God your whole spirit and soul and body be preserved blameless unto the coming of our Lord Jesus Christ.” 1 Thessalonians 5:23
Paul speaks of Christ as “the hope of glory” (Colossians 1:27) and links the glorious appearing of Christ to our personal glorification: “When Christ, who is our life, shall appear, then shall ye also appear with him in glory.” Colossians 3:4 This glorified state will be our ultimate separation from sin, a total sanctification in every regard. “Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when he shall appear, we shall be like him; for we shall see him as he is.” 1 John 3:2
To summarize, “sanctification” is a translation of the Greek word hagiasmos, meaning “holiness” or “a separation.” In the past, God granted us justification, a once-for-all, positional holiness in Christ. Now, God guides us to maturity, a practical, progressive holiness. In the future, God will give us glorification, a permanent, ultimate holiness. These three phases of sanctification separate the believer from the penalty of sin (justification), the power of sin (maturity), and the presence of sin (glorification).