Sanctification in the Bible refers to the process of being made holy or set apart for God's purpose. It encompasses both a definitive act and a progressive journey in the life of believers. In the Old Testament, the term often relates to the consecration of people or objects for sacred use, as seen in Exodus 19:10, where the Israelites are instructed to consecrate themselves before encountering God. The concept highlights God's holiness and the need for His people to reflect that holiness in their lives.In the New Testament, sanctification is closely associated with the work of the Holy Spirit and the believer's transformation into the likeness of Christ. Paul emphasizes this in 1 Thessalonians 4:3, stating, "For this is the will of God, your sanctification," indicating that it is God's desire for believers to grow in holiness. Additionally, Hebrews 10:14 notes that through Christ's sacrifice, believers are made perfect, signifying the positional aspect of sanctification, while Philippians 2:12-13 illustrates the ongoing aspect, where believers are called to "work out your own salvation with fear and trembling," as God works in them to will and to act according to His purpose. Thus, sanctification is both an initial setting apart for God's work and a lifelong journey of spiritual growth and moral integrity.