What does "filling up what is lacking in Christ's afflictions" mean? (Colossians 1:24)

In Colossians 1:24, the apostle Paul makes a statement that strikes us as odd: "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."  This is one of the most difficult statements of the letter and perhaps in the New Testament.  What is “lacking in Christ’s afflictions” and how does Paul “fill them up”?  

We can start by saying what he doesn’t mean.  He isn’t saying that there is something lacking in Christ’s death to save us from our sins.  In this letter, he has already exalted Christ as the Lord of redemption whose death made it possible for us to have peace with God (Colossians 1:20).  Jesus’ death in our place completely paid for our sins.  For all those who trust in him, their record of debt is forgiven.  It’s canceled (Colossians 2:14).  So there is nothing lacking in Christ’s suffering or afflictions or death in regard to their ability to save us.  With that being said, there are two main interpretations for what this means.

First, "Christ's afflictions" may refer to what are called the “messianic woes” (cf. Matthew 24:4-14).  Christ’s first coming initiated the last days (e.g. Acts 2:16, Hebrews 1:2).  Everything between Christ's first coming and Christ's second coming are the last days.  During that time, it was expected that those who follow the Messiah/Christ would experience a certain amount of suffering before Christ would return (e.g. Revelation 6:9-11).  So how is Paul filling up what is lacking in those afflictions that Christians will endure in Christ's name?  In a sense, he is filling up part of the "quota" of afflictions that are required before Christ returns.  This is why he rejoices in his suffering and why it benefits the church: because Paul is filling up the quota, other Christians don't have to and he is hastening Christ's return.  In favor of this view is the fact that "mystery" is about God's plan that is revealed in the future or the "last days" (cf. Dan 2:18, 19, 27, 28, 29, 30, 47) and Christians were expected to undergo suffering during those days (e.g. Matthew 24:13-14; John 15:18-16:4).  Revelation 6:9-11 even points to there being a specific amount to be endured.

The second interpretive option takes "Christ's afflictions" to mean "Christ's own afflictions."  Thus Paul is filling up a lack in Christ's own afflictions.  What is lacking in Christ’s afflictions?  Answer: Not everyone saw them personally.  At the time Paul is writing this letter, it has been about 30 years since Jesus died.  The Colossians didn’t see Jesus suffer and die on a cross.  But as Paul undergoes hardships, afflictions, and suffering to spread the message about Christ, the church is seeing a representation of Christ’s sufferings.  The main point Paul is making is this: I rejoice in my sufferings because as I suffer in making Christ known, you are seeing a physical representation of Christ’s afflictions on your behalf.  I rejoice in this because it is of benefit to Christ’s body, the church.  So in Christ’s absence, Paul is suffering like Christ did in service to the church, which gives people a picture of what Christ has done on their behalf.  In favor of this view is that it connects with Paul's commission to be a servant of Christ to the Gentiles which would involve suffering (cf. Acts 9:15-16; Colossians 1:27).  It also connects well with the point Paul is making in Colossians 1:3-2:4, which is that the gospel is valid; it is true and powerful.  As part of that, he speaks of his own ministry as a servant of the gospel (1:23 and 1:25) which includes demonstrating how Christ suffered by suffering as one of his representatives.  Furthermore, "to fill up a lack" is used elsewhere to speak of completing a task in someone’s absence or on their behalf (cf. 1 Cor 16:17, Phil 2:30).  So Paul would be presenting Christ's own afflictions through his suffering in Christ's absence.  Plus, this option doesn't exclude Scripture's clear teaching that Christ's followers would suffer like him during these "last days" before he returns.  For these reasons, this second option seems to have the most explanatory power.

We can understand suffering in Christ's name when we connect it with the work of prophets in the Old Testament.  Jesus saw himself as a prophet and like many of the Old Testament prophets, he was rejected for his message.  As Jesus calls others to follow him and spread his message, he tells them to expect to suffer like he did and like the prophets before him (Matt 5:11-12; James 5:10).  If the world hated him, the world will also hate his followers (John 15:18).  Suffering for Christ’s name is closely associated with not denying him before others (Matt 10:22; 2 Tim 2:12).

For those of us who are followers of Jesus, he has commissioned us to tell people the news about him - the gospel - no matter the consequences.  But usually we do just the opposite: we are so afraid of the consequences that we tell no one about him.  Jesus came as a prophet with a message he knew people needed to hear and gave his life for it.  Similarly he calls us to lose our lives for his sake and for the gospel’s (Mark 8:35).  We must stand on the conviction that this message is true and that people need to hear it.  It is the most important thing they will ever hear in their lives.