when it is used as a comparison or contrast as it is here, carries the idea of something that comes as a replacement. In other words, whilst we had grace and truth before Christ—through the law and priesthood given by Moses—it is through Jesus Christ himself that we receive the fullness of both grace and truth (v 14). Grace in the Old Testament has been exchanged—replaced—for the fullness of grace in Christ. That is the meaning of ‘grace upon grace’. The difference is as great as between this sad