Thank you TriuneUnity for explaining the difference in the Lutheran tradition.
Are you talking about Paul in this verse?
**Colossians 1:23b-24 **
…whereof I Paul am made a minister. Who now rejoice in my sufferings for you and fill up those things that are wanting of the sufferings of Christ, in my flesh, for His body, which is the church
Yes. What was “lacking” in Christ’s afflictions was the future suffering of all who (like Paul) will experience great affliction for the sake of the gospel, as Paul described, e.g., in 2 Cor. 1:8–10. (Cf. Phil. 2:30, where Paul tells the Philippians that Epaphroditus risked his life “to complete [Gk. anaplēroō] what was lacking [Gk. hysterēma] in your service to me”.) Paul’s sufferings are the means God uses to extend the message of the gospel to others. In a very real way, our suffering does the same exact thing.
I don’t quite understand your statement that you offer yourselves as a sacrifice to God rather than do sacrificial actions.
Rom 12:1: I appeal to you therefore, brothers, by the mercies of God, to present your bodies as a living sacrifice, holy and acceptable to God, which is your spiritual worship.
Eph 5:2: And walk in love, as Christ loved us and gave himself up for us, a fragrant offering and sacrifice to God.
1 Pet 2:5: you yourselves like living stones are being built up as a spiritual house, to be a holy priesthood, to offer spiritual sacrifices acceptable to God through Jesus Christ.
Sacrificial language from the OT is used to denote the new life of Christians, and this means that the word bodies here refers to Christians as whole persons, for both body and soul belong to God. They are a living sacrifice, meaning that they are alive from the dead since they enjoy new life with Christ. “Living” also means that they will not be put to death as OT animal sacrifices were, for Christ has fulfilled what was predicted by those sacrifices. Whereas OT worship focused on offering animal sacrifices in the temple, Paul says that spiritual worship in a broad sense now includes offering one’s whole life to God. While the literal offerings of the OT system have been done away with in Christ, the principle behind them of costly devotion to God remains.