In this passage, Paul highlights that the suffering he is going through is a source of joy simply because it is for the church’s sake and the continuous illumination of the gospel to the world. We also get to participate in this high stakes labor of love and eternity, finding every opportunity to reveal the mystery of the gospel wherever we go.
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. To them God chose to make known how great among the Gentiles are the riches of the glory of this mystery, which is Christ in you, the hope of glory. Him we proclaim, warning everyone and teaching everyone with all wisdom, that we may present everyone mature in Christ.