Filling Up What is Lacking in Christ's Afflictions?
“Now I rejoice in my sufferings for your sake, and in my flesh, I am filling up what is lacking in Christ's afflictions for the sake of his body, that is, the church, of which I became a minister according to the stewardship from God that was given to me for you, to make the word of God fully known, the mystery hidden for ages and generations but now revealed to his saints. To them, God chose to make known how great among the Gentiles are the riches of the glory of this mystery, which is Christ in you, the hope of glory.” (Colossians 1:24-27)
What Paul Did Not Mean
When I read this passage for the first time I was perplexed. What did Paul mean by “I am filling up what is lacking in Christ's afflictions”? It surely cannot mean that Christ’s redemptive work was somehow incomplete and that Paul was ‘completing’ it. The writer of the book of Hebrews teaches us that “we [those who believe in Christ] have been sanctified through the offering of the body of Jesus Christ once for all ” and that “by a single offering he [Christ] has perfected for all time those who are being sanctified” (Hebrews 10:10 & 14). Paul definitely believed in and preached the sufficiency and completeness of Jesus’s redemptive work as clearly seen in his letters (Ephesians 1:7-14; Ephesians 2:8-9; Romans 5:1-2).
What Did Paul Mean?
Looking closely at Colossians 1:24-27, Paul is saying that God gave him a ministry: to “make the word of God fully known”. What is to be made fully known? It is “the mystery hidden for ages and generations but now revealed to his saints”, which is that Salvation is also for the Gentiles. Christ came to save both the Jews and the Gentiles, making them fellow heirs of the promises in Christ (Colossians 1:26; Ephesians 3:6).
Though prophesied in the Old Testament and planned before the foundation of the world, this mystery was hidden from Man’s understanding until it was revealed in the New Covenant. When Jesus was on earth, his primary mission was to bring the good news of the kingdom to the Jews first (Matthew 15:22-27; Matthew 10:5–6), even though he healed and saved some gentiles (Matthew 15:27-28; John 4:7;39-41; Luke 7:1–10). After Jesus ascended, the Holy Spirit began revealing this truth to His church through the apostles (Acts 10:34-38; 11:1-18; Ephesians 3:1-14).
This is what Paul means in Colossians 1:24-27. The time for God’s Plan to make this mystery fully known to the Church and to preach the good news to the gentiles had now arrived. Jesus charged and empowered Paul to do so; and this mission came with many afflictions: “For this I toil, struggling with all his energy that he powerfully works within me”.
In Summary
So, what is Paul filling up that is lacking in Christ's afflictions? Not Christ’s redemptive work. That is a work that no man but Jesus Christ alone could accomplish; and it is complete, sufficient, and done once and for all!
Paul was afflicted with the hardships that come with preaching the good news of the Kingdom of God to Gentiles, a work that Jesus reserved for his apostles after He ascended into heaven.