Colossians 1:24 has consistently baffled and bothered Christians for centuries. Understandably so! Look at it again: "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." Here are a few of the interpretive possibilities, concluding with the two I find most convincing.
First, let's be clear about what this text does not mean. Paul is not saying that the redemptive sufferings of Jesus on the cross are deficient or incomplete or need to be supplemented by something that Paul or any of us might supply. I say this for several reasons. (a) Everywhere in his epistles, Paul says the opposite: Christ's death has once for all secured eternal redemption and is perfect and altogether sufficient (cf. Col. 1:12-14, 19-20; 2:13-14). (b) Jesus himself said "It is finished" (John 19:30). (c) Every other NT author says the same (see Hebrews 1:3; 9:12-14, 24-28; 10:11-14; etc.) (d) The word translated "afflictions" is never used in the NT of Christ's redemptive work at Calvary. Whereas the persecution and abuse he experienced on the earth were part of his messianic calling and qualified him to serve as our savior (see esp. Hebrews 2:10,17-18), it was his suffering and death on a cross that satisfied the wrath of the Father and secured our forgiveness.
Second, some have said that Paul is referring to the afflictions he endures "for the sake of Christ" in order to glorify him and advance the cause of the kingdom. This is true enough, but does not explain the phrase, "what is lacking in Christ's afflictions," nor accounts for how Paul can fill them up or complete them.
Third, others appeal to a typological meaning. Paul, they argue, thought of his sufferings as being like those of Christ. The sufferings of Jesus were a type or prefigurement of what all Christians would encounter. Paul's sufferings, then, correspond to those of Jesus. Again, this is true enough, but fails to explain the "lack" in what Christ suffered or how Paul filled them up.
Fourth, there is the eschatological view. Here, the afflictions of Christ refer not to what Jesus suffered but to those trials and tribulations that immediately precede the end of the age, what some have called the "Messianic woes." The idea is that there is a prescribed amount or definite measure of afflictions that Christians must endure before the end of the age. That limit, that quota, as it were, of messianic woes has not yet been reached or filled up. There is, therefore, a lack or deficiency which Paul by his suffering hopes to fill. The sufferings of the apostle, together with the sufferings of all believers, contribute to the sum total of these afflictions.
The final two views are more likely than any of the first four. I often find myself vacillating between them.
The fifth option has been defended by John Piper (Desiring God: Meditations of a Christian Hedonist, 2003). "Paul's sufferings," he explains, "complete Christ's afflictions not by adding anything to their worth, but by extending them to the people they were meant to save. What is lacking in the afflictions of Christ is not that they are deficient in worth, as though they could not sufficiently cover the sins of all who believe. What is lacking is that the infinite value of Christ's afflictions is not known and trusted in the world. . . . So the afflictions of Christ are 'lacking' in the sense that they are not seen and known and loved among the nations. They must be carried by the ministers of the Word. And those ministers of the Word 'complete' [or 'fill up'] what is lacking in the afflictions of Christ by extending them to others" (268).
What is lacking, then, in Christ's afflictions is not propitiation but presentation. In other words, the sufferings of Jesus fully satisfied the wrath of God, but there is lacking "a personal presentation by Christ Himself to the nations of the world. God's answer to this lack is to call the people of Christ (people like Paul) to make a personal presentation of the afflictions of Christ to the world. In doing this, we 'fill up what is lacking in Christ's afflictions.' We finish what they were designed for, a personal presentation to the people who do not know about their infinite worth" (269).
The amazing think about this text is how Paul envisions himself (and others) filling up this lack. It is in his "flesh"! In other words, "God intends for the afflictions of Christ to be presented to the world through the afflictions of His people. . . . Our calling is to make the afflictions of Christ real for people by the afflictions we experience in bringing them the message of salvation. Since Christ is no longer on the earth, He wants His body, the church, to reveal His suffering in its suffering" (269-70).
Sixth, and finally, it may be that in some sense Paul is experiencing afflictions in the place of Jesus, afflictions that Jesus otherwise would have endured were he on earth. By doing so Paul is convinced that he is providing an example of endurance and faith that will encourage and be of benefit to the Colossians.
The key to this final option is the concept of a spiritual union that exists between Christ and his people. We read of something similar in Paul's encounter with Jesus on the Damascus Road – "And falling to the ground he [Saul/Paul] heard a voice saying to him, 'Saul, Saul, why are you persecuting me?' And he said, 'Who are you, Lord?' And he said, 'I am Jesus, whom you are persecuting'" (Acts 9:4-5; cf. Gal. 2:20; Phil. 3:10). Everything done to the body of Christ, the church, is done to Christ himself, and vice versa.
The afflictions of Paul were the afflictions of Christ: the latter suffered in and with the former because of their spiritual union. In a sense, the sufferings of Paul (and of all Christians) are simply the continuation of the world's quarrel with our Lord. Jesus, because of the brevity of his earthly life, did not bear the full brunt of the world's hatred and animosity. Thus, we are the objects of it in his place.
The world hated and afflicted Jesus without ceasing. But since he is not here, their arrows of persecution, meant especially for him, strike his followers. By virtue of our spiritual union and identity with him, as well as our commitment to him, we endure the persecution and affliction which he otherwise would experience. What the world believes is lacking in his suffering, we fill up. We bear the afflictions which are still intended for him (see especially John 15:18-21; 2 Cor. 1:5; 4:10; Gal. 6:17). As Mark 13:13 states, "You shall be hated by all men for my name's sake."
Whichever of these last two options proves to be correct (or perhaps a combination of them, or even another view we have not considered), the point is the same: the calling of Christians is to willingly and joyfully endure suffering for the sake of Christ and his kingdom, for the sake of Christ and his body, the church. In this way we are seen to be his own. In this way others see him, through us, in his love for sinners. In this way we "share his sufferings, becoming like him in his death" (Phil. 3:10).
For the sake of his body, the church,