Jason Helopoulis’s “Rejoice in suffering” contains much of value. There is, however, one thing he says that reminds me of the Roman Catholic doctrine of the “Treasury of Merit,” which teaches that the overflow of the sufferings of Mary and the “saints” are stored up and applied to “indulgences.” Helopoulis uses Colossians 1:24 as a key text. Later, we shall see how others interpret this text.
Here is Helopoulis: (I have italicised the salient portion).
“We can also rejoice in suffering because of the benefit it has for others. One of the most curious texts in the Scriptures is Colossians 1:24 when Paul says, “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…” Paul is rejoicing in his suffering, because it is not only a benefit to himself, but also to others. Paul is alluding to the fact that the Church must endure a certain measure of suffering before the return of Christ. This suffering has been appointed by God and He has determined its breadth and depth. It appears to be a set and fixed amount and Paul is fulfilling some of this appointed suffering. And any suffering that he can endure lessens the amount left for the rest of the body of Christ. I have often found this truth to be comforting in the midst of trial. My suffering is not just for me, it is also for others. There is an unseen benefit that is accruing for the entire body of Christ. The rest of the Church will suffer less as I endure this trial for the glory of God.”
Here is the Roman Catholic view
The merits of Christ, since they are infinite, comprise most of those in the treasury of merits. By applying these to believers, the Church acts as Christ’s servant in the application of what he has done for us, and we know from Scripture that Christ’s work is applied to us over time and not in one big lump (Phil. 2:12, 1 Pet. 1:9).
“But what about the merits of the saints—by the doctrine of indulgences aren’t the saints made co-saviors with Christ?”
Not at all. At best they would only be saving us from temporal calamities, which any human may do (and should do!) for another without blaspheming Christ. Besides, the saints have the ability to please God because the love of God has been put in their hearts (Rom. 5:5). It is God’s grace that enables them to please to him. His grace produces all their good actions, and his grace is given to them because of what Christ did. The good actions of the saints therefore are produced by Christ working through them, which means Christ is the ultimate cause of even this temporal “salvation.” “Should we be talking along these lines? Isn’t it better to put all of the emphasis on what Christ alone?”
No. If we ignore the fact of indulgences, we neglect what Christ does through us, and we fail to recognize the value of what he has done in us. Paul used this very sort of language: “Now I rejoice in my sufferings for your sake, and in my flesh I complete what is lacking in Christ’s afflictions for the sake of his body, that is, the church” (Col. 1:24).
(Jim Aiken “A Primer on Indulgences”).
And a Protestant view:
Fill up that which is behind of the afflictions of Christ (Colossians 1:24).
Paul does not here claim for himself extra merit, to be placed in the “Treasury of Merit” for the assistance of souls in purgatory. He was writing from prison, where he was suffering for preaching the Gospel which his Lord had provided at the cost of His sufferings on Calvary. The Lord Jesus had told His disciples that they would be hated of all men for His name’s sake, and so indeed it came to pass, with them and with Paul. (See II Corinthians 11:23-28 where Paul recalls the suffering he had already endured as a preacher of the Gospel).
I suggest John Gill says it best.
for his body’s sake, which is the church;
not in the room and stead of the church, and people of Christ, as were the sufferings of Christ personal; or to exempt them from sufferings who all have their share in this life; nor for their sins to make reconciliation for them, and procure the remission of them; nor to redeem them, or obtain salvation for them, all which is completed by Christ; but for their good and profit, that the Gospel might continue and be blessed to the conversion of many, for the increase of the church and additions to it, and for the furtherance of the Gospel, and that such who professed it might be established and confirmed in it, by the sufferings of the apostle for it: and such good effects did follow upon his sufferings and afflictions; they were for the consolation of many souls, the strengthening of weak believers, and causing even preachers of the Gospel to wax more confident, and more boldly preach the Gospel without fear of man.