Although the covenant was a relatively known theme among sixteenth-century early Reformers, Bullinger’s theology —as reflected in his treatise A Brief Exposition of the One and Eternal Testament or Covenant of God (hereafter Covenant of God) — develops further Zwingli’s notion of the covenant. Although we can’t say that the covenant is a central hermeneutical principle to understand all Bullinger’s theology, his development of the covenant offers some good insights.
Testamentum as Covenant
Due to the diversity of meanings, Bullinger starts clarifying his understanding of the term ‘testamentum.’ He understands ‘testamentum’ as an oath-based promise taking into account what Scripture affirms in Luke 1:72-73, Acts 3:25, Genesis 15 and 17:1-14. The discussion of this term happens thus in the first part of this work where Bullinger discusses the pervasiveness of the covenant motif in the Old Testament, referring to Abraham and his descendants. For Bullinger, the covenant God celebrates with humanity is not a product of any human work (or merit). On the contrary, it is something that God has freely done (cf. McCoy and Baker, 104-5). Bullinger argues that God’s decision to join in covenant with humanity is the starting point of true religion. Although this is crucial because it locates salvation in God alone, the covenant is not unilateral. God has established ‘conditions’ (i.e. God’s demands and human responsibilities) that humanity must accept.
The Spiritual Seed of Abraham as Faithful Members of the Covenant
Bulling argues that in the Old Testament the covenant also had a spiritual dimension, sometimes overlooked. Against common belief, the reference to a “spiritual seed of Abraham” is not a notion introduced exclusively in Christian history, but it is back to the Old Testament. Bullinger offers, for example, the comparison of Jer. 4:4 with Rom. 2:28-29. Claiming that the same Spirit who spoke in the OT and NT regarding the seed of Abraham, Bullinger then suggests that the ‘carnal seed’ does not refer to the whole physical seed of Abraham but only to those “adults who have neglected the true piety of the soul” putting their faith in the visible signs of the covenant, e.g., circumcision (Cf. McCoy and Baker, 107). With this, Bullinger suggests the continuity of the covenant of grace through history. The covenant, which started after Adam and Eve sinned, has not been stopped or interrupted. On the contrary, the covenant of grace has developed or unfolded throughout all human history.
Another significant point is that the redefinition of ‘testamentum’ as covenant and the claim that the seed of Abraham refers to the faithful members of the covenant allows Bullinger to claim that children are also included in the covenant, even those children who were born from unfaithful parents. The context of this assertion is, of course, the physical seed of Abraham. Bullinger uses this example contra Anabaptists to argue that the children of Christians should be baptized and be accepted into the community of faith. Again, such an assertion suggests the continuity of the covenant of grace in history.
One God and One Covenant of Grace
In the third part of the treatise, Bullinger deals with the conditions of the covenant. A noteworthy aspect to note in this section is the conditionality of the covenant. It is God who holds the primacy of the covenant, who starts it, and who establishes the conditions. Although God makes his promises, the covenant is conditional in the sense that humanity is not free of responsibility: it must obey what God has established.
Thus, Bullinger suggests that the covenant is one of promises (on earth and in heaven) where God offers himself to Abraham and his descendants. God promises the land, eternal inheritance, and a relationship with the people. In this respect, Bullinger argues that the temporal possession of the land was fulfilled but not the eternal inheritance. This particularity is used by Bullinger to claim that there were both physical and spiritual promises in the conditional covenant of grace. He finds support in Heb. 11: 13-16. “Jesus is the inheritance himself,” Bullinger writes (McCoy and Baker, 110).
So far, Bullinger has focused on the promises of God. However, what is the role of humanity in this covenant? Humans are called to keep the covenant by walking before God and being upright. Bullinger explains that this means humans are called to arrange their life in every respect to God’s will (McCoy and Baker, 111). With this interpretation, besides the conditional aspect, one also confirms Bullinger’s bilateral understanding of the covenant: God acts in the covenant and humans must respond. One also finds here Bullinger’s suggestion that human obedience brings into effect the promises God has made.
Once Bullinger has clarified the responsibilities and duties of humanity in the covenant, he argues that all Scripture deals with the covenant. In order to demonstrate his argument, Bullinger claims that every part of Scripture, such as the Law, the Gospel, and the Epistles, speaks of the covenant. Even the judicial laws serve the covenant by helping the people to follow the conditions. The Gospels and the NT, for example, affirm the covenant of grace and confirm the established conditions humanity needed to obey. If all the scriptures deal with the covenant of grace, then each manifestation of the covenant will help the people of God to understand better the covenant of grace itself throughout history. There are several manifestations of the covenant, but one single covenant of grace. (cf. McCoy and Baker, 120). In other words, the covenant has a developmental and progressive aspect.
Concluding Remarks
Overall, Bullinger defends a single covenant of grace started freely by God since the creation. It is also a bilateral and ‘conditional’ covenant in the sense that humanity must accept God’s demands. God has made a series of promises to humanity, and the latter must accept and respond accordingly. Finally, the covenant has a developmental and historical character. The covenant unfolds through human history. The New Testament does not contradict the Law, but it shows a different aspect of the covenant.