Covenant lies at the heart of the biblical understand of God’s relationship to the world. Simply put, a covenant stands in contrast to a contract where parties enter into a quid pro quo arrangement. With a contract an agreement is made to protect oneself. With a covenant, one commits oneself with promises to another for the sake of the other. This concept of covenant is nothing less than the bridge between the Trinity ad intra and the self-communication of the Trinity ad extra. Scott Swain argues that all of God’s communication is “covenantal self-communication.” It is “by means of covenant…[that] God binds himself to creation in a relationship of sovereign care and commitment and binds creation to himself in a relationship of obedient service.” “By his covenantal word, God creates, redeems, and consummates the world.” 
The concept of covenant permeates, and largely structures, the entire biblical narrative. One could say that the rich variety of linguistic forms found in Scripture are all ultimately put in service to one thing: covenant. Kevin Vanhoozer concurs when he notes that “[c]ovenanting is both the substance and the form of God’s characteristic communicative action.” All Scripture must therefore be understood as covenantal discourse. God authorizes agents to speak for him, and “[b]y means of his prophets and apostolic word, God binds himself to his people and his people to himself.” In accordance with this, our reading of Scripture must also be understood as a Spirit-led covenantal activity.
The covenantal self-communication of the triune God culminates, and is fulfilled in, Jesus Christ. In Christ, Paul says, all of God’s promises are “Yes” (2 Cor. 1:20). Nothing is more crucial for a proper understanding of biblical revelation than appreciating the centrality of covenant and understanding Christ as the exhaustive “Yes” of this covenant. And Christ is the “Yes” of this covenant between God and humanity both from the side of God and from the side of humanity.
By becoming the first and only faithful human covenant partner while yet suffering the deserved punishment for all of us who have been unfaithful, Jesus becomes our new representative—our new “Adam” (1 Cor 15:45). When we place covenantal trust in him and pledge our covenant fidelity to him—when we exercise “faith”—we are incorporated into Christ and pronounced “righteous,” which in covenantal terms means we are put in a right relationship with God because we are made participants of Christ’s right-relatedness.
At the same time, in the process of fulfilling the covenant from the human side, Jesus also fulfilled the covenant from God’s side, for Jesus is not only human; he’s the human who is the eternal Word made flesh (Jn 1:14). Hence, in humbling himself to become a human, in living a life of perfect, other-oriented love, and especially by choosing to suffer the death-consequences of our covenant-breaking, Jesus demonstrated God’s loving faithfulness as our covenant partner (Rom. 5:8).
Jesus is thus the definitive “Yes” of both God and humanity within the new covenant that was inaugurated with his self-sacrificial death and was confirmed by his resurrection from the dead. And the fact God is the ultimate keeper of the covenant through the cross becomes the framework within which our thinking about all of God’s self-communication and activity in the world must take place. The meaning, purpose and character of every aspect of God’s covenantal activity must be understood in light of this culminating point.
 Swain, Trinity, Revelation and Reading: A Theological Introduction to the Bible and its Interpretation, 6-7, 4, 19, 32.
 Vanhoozer, The Drama of Doctrine, 301.
 Swain, 40.