The apostle Paul opened his letter to the believers in Philippi by explaining that he often thanked God for them in joyful prayer because of their partnership in sharing the gospel. Paul held a special affection for the Philippian church, which he had founded approximately ten years earlier. Now he expressed confidence in God’s continued work in their lives: “I thank my God upon every remembrance of you, always in every prayer of mine making request for you all with joy, for your fellowship in the gospel from the first day until now, being confident of this very thing, that He who has begun a good work in you will complete it until the day of Jesus Christ” (Philippians 1:3–6, NKJV).
Paul had seen firsthand the good work that God had begun in the Philippian believers. In Philippi, on Paul’s second missionary journey, he and his companions encountered Lydia and other women meeting by the riverside for prayer. As Paul preached, Lydia and her household were saved and baptized, and the Philippian church was born (Acts 16:11–15). Later, the Christians in Philippi conducted their house church in Lydia’s home. As the church grew, it became one of the strongest supporters of Paul’s ministry (Philippians 4:10–20).
Paul loved the Philippians deeply and desired to see them continue to grow in Christian maturity and abound in ever-increasing spiritual understanding: “I pray that your love will overflow more and more, and that you will keep on growing in knowledge and understanding. For I want you to understand what really matters, so that you may live pure and blameless lives until the day of Christ’s return. May you always be filled with the fruit of your salvation—the righteous character produced in your life by Jesus Christ—for this will bring much glory and praise to God. so that they will be blameless until the day of Christ” (Philippians 1:9–11, NLT).
At the time of our salvation, God begins His work in us. We are made alive in Christ—regenerated, made new (2 Corinthians 5:17). Then, through an ongoing, lifelong process called sanctification, God finishes, perfects, and completes His work in us. Paul referred to the process when he said, “He who has begun a good work in you will complete it until the day of Jesus Christ” (Philippians 1:6, NKJV). Spiritual growth ought to continue in steadfast believers until the day Jesus Christ returns (2 Peter 3:18; 1 Thessalonians 5:23).
A brief biblical definition of sanctification is “the Holy Spirit’s work of setting believers apart to be made holy or made like God.” Sanctification is a three-phase process. At the moment of salvation, Christians enter positional sanctification. Jesus’ work on the cross is a finished work—believers stand positionally sanctified as though they already are made holy before God, even though they are not yet completely holy in practice: “For by one sacrifice he [Jesus] has made perfect forever those who are being made holy” (Hebrews 10:14).
Progressive sanctification is phase two, in which God, who has begun a good work in us at salvation, continues to transform us into His image, saving us from the practice and power of sin. After the initial cleansing from sin, the committed Christian begins to undergo a daily process of spiritual renewal (Colossians 3:10). The Bible also calls this phase “the sanctifying work of the Spirit,” as the Holy Spirit is the chief agent working in the believer to produce the character of God and the fruit of holiness (1 Peter 1:2; cf. 1 Corinthians 6:11; 2 Thessalonians 2:13; Galatians 5:22–23).
From the moment God begins His good work in us until the day of its completion, the Holy Spirit is chipping away, renovating our character, day by day reforming us into partakers of the holy nature of God. God does the work, but believers are also meant to be active in the process, yielding to the effort (Romans 6:13, 19; 12:1) and pressing on toward the upward call to holiness (Hebrews 12:14; Philippians 3:12–14).
God began a good work in us at salvation and then called us to live out the progressing development of being made into His image. The Christian walk is a pathway of ongoing growth. The journey brings us ever closer to God until His work in us is perfect and complete on “the day of Jesus Christ”—that is, the day of Christ’s return when we see Him (Colossians 3:4; 1 Thessalonians 5:23). Complete sanctification is the third phase, also known as glorification.
From the very beginning, throughout the continuation, and until the final stroke, God is working in us (Philippians 2:13). He is the Master Craftsman who never gives up on us (Ephesians 2:10; 2 Corinthians 1:21–22). The Lord’s salvation, His glorious redemption of His people, will reach its crowning culmination when Jesus Christ returns. Only then will God, who has begun a good work in you, put His finishing touch on you.