In Colossians 1:24 Paul writes, “Now I rejoice in what I am suffering for you, and I fill up in my flesh what is still lacking in regard to Christ’s afflictions, for the sake of his body, which is the church.” We know that Christ’s death was the fully sufficient payment for our sin, so what did Paul mean when he said that something in Christ’s afflictions was “still lacking”?
Paul is not saying that there was anything lacking or deficient in the sufferings that Christ endured to atone for the sins of the world. Rather, Paul is saying that his (Paul’s) suffering for Christ’s sake was still lacking. Although he had suffered much affliction, Paul was not yet conformed to the Savior in his sufferings. Other translations of Colossians 1:24 bring out Paul’s meaning more clearly: “I am glad when I suffer for you in my body, for I am participating in the sufferings of Christ that continue for his body, the church” (NLT); and “Now I rejoice in my sufferings on your behalf. And with my own body I supplement whatever is lacking [on our part] of Christ’s afflictions, on behalf of His body, which is the church” (AMP). Note that the lack is on Paul’s part, not Christ’s.
Paul also speaks of his sufferings in relation to those of Christ in 2 Corinthians 1:5: “For just as we share abundantly in the sufferings of Christ, so also our comfort abounds through Christ.” Paul’s sufferings on behalf of the church were not without purpose. They enabled him to comfort other believers going through difficulties. This is also part of what Paul means in Colossians 1:24 when he refers to this suffering taking place “for the sake of the body,” meaning the Body of Christ, the body of believers.
The apostle Paul certainly endured many sufferings for Christ during his ministry. He encountered beatings, imprisonment, stoning, and much more (2 Corinthians 11:23–28). The deeper his troubles, the more deeply Paul saw a connection with the Lord who had suffered so much for him. In Galatians 6:17 he writes, “I bear on my body the marks of Jesus.” Paul’s afflictions were no surprise to him. When Paul was commissioned for his task, the Lord Jesus said, “I will show him how much he must suffer for my name” (Acts 9:16).
Jesus taught that in this world we would have trouble (John 16:33). “If the world hates you, keep in mind that it hated me first” (John 15:18). Paul and Barnabas, on the first missionary journey, certainly saw the truth of Jesus’ words as they revisited the cities where they had planted churches, “strengthening the disciples and encouraging them to remain true to the faith. ‘We must go through many hardships to enter the kingdom of God,’ they said” (Acts 14:22). Paul’s teaching that Christians should expect suffering and that his own suffering filled up what was “lacking” is diffused throughout his work. But the theme of joyfulness in suffering is also present. That’s why Paul could say, “I rejoice in what I am suffering for you” (Colossians 1:24; cf. Philippians 2:17).
In summary, Paul was not suffering to merit grace or earn his salvation; neither was he complementing or completing the sufferings that Jesus personally experienced. Rather, Paul saw his suffering as helping conform him into the image of Christ. We, too, can view our trials and afflictions as a means to make us more like Jesus, as we are “predestined to be conformed to the image of his Son” (Romans 8:29). Until we join Christ in glory, we will experience some of the same suffering that Jesus Christ did as part of God’s sanctifying process.