1:24 Who now rejoice in my sufferings for {r} you, and fill up {s} that which is behind of the afflictions of Christ in my flesh for his body's sake, which is the church:
(r) For our profit and benefit.
(s) The afflictions of the Church are said to be Christ's afflictions, by reason of that fellowship and knitting together that the body and the head have with one another. And this is not because there is any more need to have the Church redeemed, but because Christ shows his power in the daily weakness of his own, and that for the comfort of the whole body.
1:24 Who now rejoice. Rather, I now rejoice.
My sufferings for you. He was a prisoner and a sufferer because he preached the gospel of the Gentiles.
And fill up that which is behind of the afflictions of Christ. Christ endured afflictions for us. We must have a fellowship of his sufferings (1Pe 4:13). Paul also suffers that he might share the afflictions of Christ. Not only did he suffer with Christ, but Christ suffers with his afflicted people. See Ac 9:4. Hence, afflictions suffered for Christ may be called his afflictions. All the suffering required for the sake of the church is behind of the afflictions of Christ.
1:24 Now I rejoice in my sufferings for you, and fill up - That is, whereby I fill up. That which is behind of the sufferings of Christ - That which remains to be suffered by his members. These are termed the sufferings of Christ, Because the suffering of any member is the suffering of the whole; and of the head especially, which supplies strength, spirits, sense, and motion to all. Because they are for his sake, for the testimony of his truth. And these also are necessary for the church; not to reconcile it to God, or satisfy for sin, (for that Christ did perfectly,) but for example to others, perfecting of the saints, and increasing their reward.
1:24-29 Both the sufferings of the Head and of the members are called the sufferings of Christ, and make up, as it were, one body of sufferings. But He suffered for the redemption of the church; we suffer on other accounts; for we do but slightly taste that cup of afflictions of which Christ first drank deeply. A Christian may be said to fill up that which remains of the sufferings of Christ, when he takes up his cross, and after the pattern of Christ, bears patiently the afflictions God allots to him. Let us be thankful that God has made known to us mysteries hidden from ages and generations, and has showed the riches of his glory among us. As Christ is preached among us, let us seriously inquire, whether he dwells and reigns in us; for this alone can warrant our assured hope of his glory. We must be faithful to death, through all trials, that we may receive the crown of life, and obtain the end of our faith, the salvation of our souls.