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, of which I became a minister according to the stewardship from God that was given to me for you, to make the word of God fully known, the mystery hidden for ages and generations but now revealed to his saints. -Col 1:24-25
Did the Apostle Paul just say that “he fills up what is lacking in the afflictions of Christ?" That seems a little at odds with Jesus’ statement, "It is finished." Perhaps salvation isn't complete? Jesus suffered a lot, but maybe a little more suffering is required from each of us? Is this how we are to read Paul's words? If not, what in the world is he saying?
Before you throw in the towel on grace alone to pick up a whip and join a monastery, let me take a shot at explaining Paul’s statement.
Nothing is lacking in the suffering, affliction, and work of Christ when it comes to salvation. Everything Jesus did was sufficient for the redemption of the world. The finished work of Christ is objectively true for the whole of creation. However, imagine if someone forgave you but you never knew it. Imagine if you were fighting a war that had ended a long time ago, but no one told you.
The subjective benefits of Christ’s objective work are applied via faith in that work. That faith is created and sustained by Word and Sacrament. Paul is not saying that the work of Christ is insufficient to save. He is saying, the wholly finished and sufficient work of Christ doesn't proclaim itself. Faith comes by hearing all that God has done to save sinners (Romans 10:17). All the afflictions of Christ lack are the proclamation of all they have accomplished. The war is over! Forgiveness, salvation and eternal life are yours! Yours and the whole world’s! This is what Paul has committed his life in the flesh to: making the word of God fully known.
When people ask me why we spend so much time, energy and resources writing books and articles, producing podcasts, creating videos and holding events; I point them to these words of Paul. And while we are not Paul, we have the same message. We have the same gospel. The same good news that God in Christ has reconciled the world. That the work of Christ was sufficient for each and every one of us. All we can do now is proclaim it to as many people as possible, in as many ways as possible. To every corner of the earth… and the internet.