Personal Presentation of the Sufferings

Excerpt from an Ask Pastor John response

What does Paul mean when he says he is "filling up what is lacking in Christ's afflictions"?

I think it's plain from the context and the wider teachings of Paul that he does not mean that he fills up by his sufferings what is lacking in the atoning worth of the death of Christ. When Jesus says, "It is finished" on the cross, all that had to be done to pay for the sins of all God's people was done. And nothing could be added.

So when Paul says, "By my sufferings I fill up what is lacking in the afflictions of Christ," what he means is that the one thing lacking in the sufferings of Christ is the offer of those sufferings in person to those for whom he died. So in essence he is saying, "Alright, I will take the message of the cross—where Christ suffered for lost people—and in my own missionary sacrifices I will take that message to them and say, 'In me behold the love of God, as I sacrifice to come to you and preach to you, and risk my life and imprisonment to preach the gospel.'" That's the thing that he provides that is lacking.

Christ cannot personally offer himself to people today. In and through God's people—especially missionaries—he offers himself to them. And so they fill up what is lacking, namely, the personal presentation of the sufferings of Christ in their own bodies.