Blog 210: 4.14.20 - 4.14.26
Calvin argues that the Old Testament sacraments "looked to the same purpose to which ours now tend: to direct and almost lead men by the head to Christ" (4.14.20). In particular, circumcision, baptisms, and sacrifices in the Old Testament all served as signs and seals of God's promises by which God's people looked forward in faith to the promised Messiah (4.14.21).
But New Testament sacraments serve to show forth Christ yet more clearly. "As for our sacraments," Calvin writes, "the more fully Christ has been revealed to men, the more clearly do the sacraments present him to us from the time when he was truly revealed by the Father has he had been promised. For baptism attests to us that we have been cleansed and washed; the Eucharistic Supper, that we have been redeemed" (4.14.22).
There is a fundamental continuity between the Old and New Testament in terms of the substance of the promises held out in the sacraments: "whatever is shown us today in the sacraments, the Jews of old received in their own--that is, Christ with his spiritual riches" (4.14.23).
The discontinuity between the Old and New Testaments comes not with the substance, but with the signs themselves. According to Colossians 2:12, "baptism is today for Christians what circumcision was for the ancients" (4.14.24). Likewise, the Old Testament sacrificial system and especially Passover found their fulfillment in Christ and are replaced by the Supper, which declares the Lord's death until he comes (4.14.25).