In Col 1:21-29, Paul principally described his ministry to Gentiles. He discussed the Gentiles reconciliation in vs. 21-23 and his ministry in vs. 23-29.
According to Col 1:21-22, when Gentiles get saved, we are reconciled in the body of Christ’s flesh through death. Paul wrote to the Ephesians about our reconciliation in Eph 2:12-17. We “are made nigh by the blood of Christ,” and become “one new man” with saved Jews in the body of Christ. This is remarkable, since we were alienated and enemies in our mind by wicked works, Eph 4:17-19, Rom 5:10.
According to Col 1:22-23, as a result of our reconciliation in Christ, he will present us holy and unblameable and unreproveable in his sight, conditioned on two things. This is extraordinary, considering our former wicked works and our alienation from Christ.
The first condition is that we “continue in the faith grounded and settled.” A man grounded and settled in the faith is like the man who built his house on a rock in Lk 6:47-48. If you are not grounded and settled in the faith, you are still reconciled, but you won’t be holy, unblameable, and unreproveable in his sight. Remember, at the judgment seat of Christ, you will receive the things done in your body, whether good or bad, 2 Cor 5:10.
The second condition is that we “be not moved away from the hope of the gospel.” Men tried to move the Galatians away from the hope of the gospel and nearly succeeded, Gal 3:1. Men who move away from the gospel are certainly reprovable. Paul reproved them in Gal 5:7-12, and the Lord will certainly reprove them, even if they were reconciled by the gospel they now pervert.
In Paul’s ministry to the Gentiles:
He preached the gospel – Col 1:23 – this is the same gospel that was preached to every creature, 1 Cor 15:3-4, Rom 10:18. In other words, Paul didn’t have a separate gospel just for Gentiles. The gospel is for men, 1 Tim 2:5-6.
He suffered for the church – Col 1:24 – when Jesus was on earth, he was persecuted for preaching the truth. And he told his disciples that they would likewise suffer, Jn 15:20. When the Lord saved Paul and called him, he told Ananias that “I will shew him how great things he must suffer for my name’s sake,” Acts 9:16. This is to what Paul was referring when he wrote, “that which is behind of the afflictions of Christ.” When Jesus ascended, he left this suffering of affliction to his saints, Acts 14:22, 2 Thes 1:4-5. Paul rejoiced in his suffering as Jesus instructed his disciples to do, Matt 5:11-12.
He received a dispensation of God – Col 1:25-27 – Paul received a dispensation of the grace of God to make known the mystery of Christ, “that the Gentiles should be fellow-heirs, and of the same body, and partakers of his promise in Christ by the gospel,” Eph 3:1-7. This mystery, which “hath been hid from ages and from generations” also included the revelation of “Christ in you, the hope of glory.” The disciples knew of the indwelling of Christ for saved Jews, Jn 14:18-23. What they didn’t know, until it was revealed to Paul, is that Christ would likewise indwell Gentile converts. This is the fulfillment of the word of God.
He preached to, warned, and taught every man – Col 1:28 – Paul’s objective was to present every man perfect in Christ Jesus. Therefore, he preached to (Acs 14:21), warned (Acts 20:31), and taught (Acts 18:11) every man. It’s these three things, done with the word of God, that will perfect the saints, Eph 4:11-12, 2 Tim 3:16-17.
He labored according to God’s working in him – Col 1:29 – Paul knew that the work he did was the result of God working in him, Phil 2:13. He wrote to the Corinthians, “by the grace of God I am what I am: and his grace which was bestowed upon me was not in vain; but I labored more abundantly than they all: yet not I, but the grace of God which was with me,” 1 Cor 15:10.
Conclusion: Paul’s ministry to Gentiles was “to fulfill the word of God,” Col 1:25. Jesus died for every creature, and so Paul preached to the Gentiles that they might be saved, and grounded and settled in the faith. For this he suffered. Yet, the mystery of Gentiles in the body of Christ and Christ in the Gentiles was proclaimed throughout the world. The work God did through Paul was mighty and the gospel he preached is still being preached among the Gentiles today, by the grace of God.