For centuries, Christendom has wrestled with the meaning of the cross. Theologians study debates over "theories of the atonement." Classical Protestants understand the atonement in terms of "penal substitution." In other words, Christ suffered the penal sancations of the covenant curse as our substitute. This "theory" is absolutely true according to Scripture.
One of the other popular theories of the atonement in early Christendom is the "Christus Victor" theory. This understanding is more narratival - it sees the cross as the point at which sinful men were "redeemed" or bought at a price to trick Satan. Satan thought that Christ's death would assure his program of death and destruction, not expecting that Christ would rise from the dead as the Lord of Glory. Therefore, Satan unwittingly defeated and deceived himself in seeking Christ's crucifixion.
I would like to suggest that both theories are true. Don't misunderstand, it is very good and right that the church has grown in its understanding of "penal substitution." However, to the extent that the church loses its narratival understanding of Christ conquering Satan on the cross, that is a bad thing. Indeed, Satan was deceived about the death of Jesus. The devil was foolish to believe that Christ's death would secure his victory. In fact, the cross sealed his fate forever.
On this Good Friday, I encourage you to remember that Christ died for your sins, but he also plundered the strong man's house to take back the world and restore it in His image (Matt 12:29). We celebrate the remission of our sins AND the restoration of the world (Acts 3:21) because of Christus Victor!