When we come to Christ in the Supper, we are not fundamentally doing something for him. He is, rather, doing something for us. He is supplying needy souls with the grace of the gospel. He is furnishing what we need from the resources of his sacrificial death on the cross. He is pledging to bring each of his children home to the messianic banquet where we shall enjoy in full what we now enjoy in part - life and blessing from, with, and in our Savior.The Lord\'s Supper as the Sign and Meal of the New Covenant (Short Studies in Biblical Theology) (p. 95). Crossway
Circumcision was applied to the male procreative organ, the organ by means of which God's promise to Abraham would come into being. There was, then, a fitting connection between the sign of circumcision and the promise signified. Abraham bore in his own body a physical mark intended to direct him to the divine promise to bring into the world the Redeemer of sinners. In so putting faith in God's promise, represented in the sign of circumcision, Abraham had the truth of this promise confirmed to him. Circumcision was to Abraham, therefore, both sign and seal of the covenant promise to justify sinners by the work of Jesus Christ.The Lord\'s Supper as the Sign and Meal of the New Covenant (Short Studies in Biblical Theology) (p. 49).
God's covenants with people formalize an existing, elective relationship and in this way bring life-and-death issues to the fore. In these covenants, God sovereignly administers promises with corresponding obligations.
The Lord\'s Supper as the Sign and Meal of the New Covenant (Short Studies in Biblical Theology) (p. 31).