Passage
Who now rejoice in my sufferings for you, and fill up that which is behind of the afflictions of Christ in my flesh for his body’s sake, which is the church:
Who now rejoice in my sufferings for you, and fill up that which is behind of the afflictions of Christ in my flesh for his body’s sake, which is the church:
Colossians 1:22 In the body of his flesh through death, to present you holy and unblameable and unreproveable in his sight:
Colossians 1:23 If ye continue in the faith grounded and settled, and be not moved away from the hope of the gospel, which ye have heard, and which was preached to every creature which is under heaven; whereof I Paul am made a minister;
Colossians 1:24 Who now rejoice in my sufferings for you, and fill up that which is behind of the afflictions of Christ in my flesh for his body’s sake, which is the church:
Colossians 1:25 Whereof I am made a minister, according to the dispensation of God which is given to me for you, to fulfil the word of God;
Colossians 1:26 Even the mystery which hath been hid from ages and from generations, but now is made manifest to his saints:
The verse centers on "rejoice", "sufferings", "fill", "behind", "afflictions", "christ", "flesh", and "body". It is saying that the verse draws attention to "rejoice" and "sufferings", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 23's "If ye continue in the faith grounded..." into verse 25's "Whereof I am made a minister according...", so "rejoice" and "sufferings" belong inside that flow. In Colossians context, the local focus is Christ, faith, and discipleship.
A plain takeaway is to answer the verse's own emphasis on "rejoice" and "sufferings" with trust shaped by these words, not by a vague optimism outside the passage.