The most amazing thing about Colossians 1:24 is how Paul fills up what is lacking in Christ’s afflictions. He says that it is his own sufferings that fill up Christ’s afflictions. “I rejoice in my sufferings for your sake, and in my flesh I am filling up what is lacking in Christ’s afflictions.” This means, then, that Paul exhibits the sufferings of Christ by suffering himself for those he is trying to win. In his sufferings they see Christ’s sufferings. Here is the astounding upshot: God intends for the afflictions of Christ to be presented to the world through the afflictions of his people. God really means for the body of Christ, the church, to experience some of the suffering he experienced so that when we proclaim the cross as the way to life, people will see the marks of the cross in us and feel the love of the cross from us. Our calling is to make the afflictions of Christ real for people by the afflictions we experience in bringing them the message of salvation. -John Piper, Desiring God: Meditations of a Christian Hedonist, p 269-270