Here is an exerpt from an article by Vern Poythress that relates to our Wed night study.
You can read the full article here Overview of the Bible :A Survey of the History of Salvation
The promises of God in the OT come in the context
not only of God’s commitment to his people but also of
instruction about the people’s commitment and
obligations to God. Noah, Abraham, and others whom God
meets and addresses are called on to respond not only
with trust in God’s promises but with lives that begin to
bear fruit from their fellowship with God. The relation of
God to his people is summed up in various covenants that
God makes with people. A covenant between two human
beings is a binding commitment obliging them to deal
faithfully with one another (as with Jacob and Laban in
Gen. 31:44). When God makes a covenant with man, God
is the sovereign, so he specifies the obligations on both
sides. “I will be their God” is the fundamental obligation
on God’s side, while “they shall be my people” is the fundamental
obligation on the human side. But then there are variations in the details.
For example, when God first calls Abram he says, “Go
from your country and your kindred and your father’s
house to the land that I will show you” (Gen. 12:1). This
commandment specifies an obligation on the part of
Abram, an obligation on the human side. God also indicates
what he will do on his part: “And I will make of you
a great nation, and I will bless you and make your name
great, so that you will be a blessing” (Gen. 12:2). God’s
commitment takes the form of promises, blessings, and
curses. The promises and blessings point forward to Christ,
who is the fulfillment of the promises and the source of
final blessings. The curses point forward to Christ both in
his bearing the curse and in his execution of judgment and
curse against sin, especially at the second coming.
The obligations on the human side of the covenants
are also related to Christ. Christ is fully man as well as
fully God. As a man, he stands with his people on the human side.
He fulfilled the obligations of God’s covenants
through his perfect obedience (Heb. 5:8). He received the
reward of obedience in his resurrection and ascension (see
Phil. 2:9–10). The OT covenants on their human side thus
point forward to his achievement.
By dealing with the wrath of God against sin, Christ
changed a situation of alienation from God to a situation of peace.
He reconciled believers to God (2 Cor.
5:18–21; Rom. 5:6–11). He brought personal intimacy
with God, and the privilege of being children of God
(Rom. 8:14–17). This intimacy is what all the
OT covenants anticipated. In Isaiah, God even declares that his
servant, the Messiah, will be the covenant for the people
(see Isa. 42:6; 49:8).