The gospel is more than Jesus dying on the cross. Believers are saved, not only by the death of Christ, but also by the life of Christ, and the resurrection of Christ.
And the effect of the gospel is more than just the reconciliation between God and humanity. When Jesus was buried, the tomb became the womb of a whole new creation. And on that third day, as Christ came bursting forth from that tomb, that womb, the new creation was just beginning.