From Zacharias Ursinus:
It has been shown, that a Mediator is one who reconciles parties that are at variance, as God and men. This reconciliation is called in the Scriptures a covenant…[p. 96].
This agreement, or reconciliation, is called a Covenant, because God promises certain blessings, and demand from us in return our obedience, employing also certain solemn ceremonies for the confirmation thereof…. [p. 97]
This covenant is one in substance, but two-fold in circumstances; or it is one as it respects the general conditions upon which God enters into an engagement with us, and we with him; and it is two as it respects the conditions which are less general, or as some say, as it respects the mode of its administration.
The Covenant is one in substance. 1. Because there is but one God, one Mediator between God and man, Jesus Christ, one way of reconciliation, one faith, and one way of salvation for all who are and have been saved from the bbeginning… [p. 98].
2. There is but one covenant, because the principal conditions, which are called the substance of the covenant, are the same before and since the incarnation of Christ; for in each testament God promises to those that repent and believe, the remission of sin; whilst men bind themselves, on the other hand, to exercise faith in God, and to repent of their sins.
But there are said to be two covenants, the old and the new, as it respects circumstances and conditions which are less general, which constitute the form, or the mode of administration, contributing to the principal conditions, in order that the faithful, by their help, may obtain those which are general.
IV. IN WHAT DO THE OLD AND THE NEW COVENANT AGREE, AND IN WHAT DO THEY DIFFER?
Since there is but one covenant, and the Scriptures speak of it as though it were two, we must consider in what particulars the old and the new covenants agree and in what they differ.
They agree, 1. In having god as their author and Christ as the Mediator. …
2. In the promise of grace concerning the remission of sins and eternal life granted freely to such as believe by and for the sake of christ, which promise was common to those who live under the old covenant, as well as to us; although it is now delivered more clearly, for god promises the same grace to all that believe in the Mediator….
3. In the condition in respect to ourselves. In each covenant, God requires from men faith and obedience. “Walk before me and be thou perfect.” “Repent and believe the Gospel.” (Gen. 17:1. Mark 1:15.) The new covenant, therefore, agrees with the old in that which relates to the principal conditions, both on the part of God, and on the part of man…. [p. 99]
I understand the force of this quotation, Mark. And I agree.
But whenever I read these older “definitions” of a covenant, I always cringe. To define a covenant as a device that brings together two parties that are at variance is way too restrictive. It doesn’t embrace the fulness of the meaning of covenant. God and man are in covenant before they are at variance with one another. And I’m not sure about this necessity of a mediator for every covenant. Just some off-topic thoughts.
Ursinus would agree that such a definition is too restrictive. He isn’t talking about all covenants here, nor is he saying that if something is a covenant, then it must be reconciling and have a mediator. Rather, he’s saying that the administration of grace that is reconciling and has a mediator is also a covenant.
Ursinus holds to pre-lapsarian covenant with Adam, which he terms “the covenant of nature,” something distinct from either the “old covenant” or “new covenant” of which he speaks here (the two-fold administration of the post-lapsarian covenant of grace). Moreover, he holds that this pre-lapsarian covenant, while rooted in natural law, nonetheless comes in a context of God’s gracious gifts to his creatures.
In his Commentary on the Heidelberg Catechism 9 (Eerdmans, 1954), Ursinus states that God created human beings in his own image with the “gifts” (gaben) of knowledge of himself, a desire to worship God wholly, and the ability to remain perfectly obedient. In the Latin parallel to this passage in his Catechesis Maior 210, he refers to these gifts as “grace” (gratia) and states that, in the fall, Adam and Eve “robbed themselves and all their descendents of that grace of God.” The benefits enjoyed by humanity in Adam were not merely “good things” but also divine “grace” (Commentary 34) and that state of humanity was one in which we could not persevere apart from God’s continued grace to us (Summa religiones christianae 154, 223).
Much more to be said, but perhaps that helps clarify Ursinus’ teaching.