Pressing toward the Prize
Paul immediately blocks a triumphalist reading of what he has just said. He has not already attained the resurrection goal and is not already perfected. He runs because Christ has first taken hold of him. Forgetting what lies behind and reaching forward, he presses toward the goal for the prize of God’s upward calling in Christ.
Where this fits in the story: Paul uses athletic imagery elsewhere for disciplined Christian perseverance. The order is important: he does not run to make Christ take hold of him; he runs because Christ has taken hold of him. Mature believers are therefore not people who imagine they have arrived, but people whose confidence in Christ produces focused perseverance.