Romans 16 talks about a "mystery hidden for long ages past." Collectively, scripture teaches that this mystery was the coming of Christ. Old Testament prophecies predicted both a King Messiah who would set up righteous reign, and a Suffering Servant who would be sacrificed. Prior to Christ's death no one, not even the angels or Christ's disciples understood that these two pictures were of the same person! We learn that God intentionally hid this plan from Satan, such that Christ might provide salvation for all.