Colossians 1:24
Who now rejoice in my sufferings for you, and fill up that which is behind of the afflictions of Christ in my flesh for his body’s sake, which is the church: Who now rejoice in my sufferings for you, and fill up that which is behind of the afflictions of Christ in my flesh for his body’s sake, which is the church:
Paul now rejoices in sufferings endured for the believers, bearing in his own body afflictions for the sake of Christ's body, which is the church. To fill up what remains of the afflictions of Christ is to share in hardship borne in labor for the church as a continuing part of its service. This does not add to Christ's reconciling work, which was accomplished in the body of His flesh. The suffering belongs to ministry for the church in carrying the gospel forward, making God's word known, and laboring to present every person mature in Christ. As the Father sent Christ to save the lost world, Christ sends His followers to continue His self-sacrificing work of saving the lost by enduring affliction for the church, bringing salvation to those ready to perish and present truth to those in error.
Paul's Sufferings for Church
Paul now rejoices in sufferings endured for the believers, bearing in his own flesh affliction for the sake of Christ's body, which is the church. His bodily suffering serves the church, contributing to the afflictions Christ's followers endure for the sake of that body. His sufferings endured for the church's sake are a way of serving Christ's body, belonging to his ministry for the church.
To fill up what is behind of the afflictions of Christ means that hardship borne in work for the church continues as part of its service. By enduring such affliction in his own body for the church's sake he shared in the afflictions borne by Christ's people. This filling up does not replace Christ's reconciling work, which was accomplished in the body of His flesh.
Paul's suffering belongs to carrying the gospel forward, laboring to make God's word known, and working to present every person mature in Christ. His ministry includes bearing affliction while carrying that gospel forward, as part of God's work of making the gospel known and bringing people to maturity in Christ. He could rejoice in suffering for Christ's sake because his work had delivered people from a far worse bondage into hope and peace with God. That joy was not erased by the bonds and afflictions that awaited him.
Continuing Christ's Saving Work
As the Father sent Christ into the world to save the lost world, so Christ sends His followers into the world to continue His work of saving the lost. Filling up what remains of Christ's afflictions for the sake of His body, which is the church, means sharing in the suffering involved in that self-sacrificing work. Every soul whom Christ has rescued is called to work in His name for the saving of the lost, continuing the same self-sacrificing mission by which Christ left heaven to seek the lost sheep.
This rejoicing in sufferings endured for believers, and in bodily afflictions for the church as Christ's body, belongs to the work of bringing salvation to people ready to perish. The same hardship is part of giving present truth to those in error.
Those who labor in word and doctrine have a work to arouse people from an irreligious state and to elevate them to correct views and correct practices. They are to do this by their own circumspect course, habits, customs, word, and example, taking heed to themselves. They are in no way to belittle the requirements of God, especially the fourth commandment enjoining observance of the Sabbath. They are to keep it strictly and to order their own arrangements rather than violating it for convenience or human demands.
The verse gives instruction of the highest value. It teaches that the religion of Christ makes all who possess it truly benevolent, countenancing no littleness and no mean transactions. It gives true Christians a nobility that allows none of the cheap covetous actions that disgrace the doer. It requires men in responsible positions to make straight paths for their feet, lest the lame be turned out of the way.