Parsonsmom,
I appreciate your question and I will try to answer it fully here but keep in mind it is not a short answer for there are a lot of verses to look at. Ill go through most of them, but I will focus on the parts referring to will, promise, and covenant.
Gal. 3:8
All the nations be blessed: The citation combines the Greek version of Gen. 12:3 and Gen. 18:18. God promised blessings for Abraham that extended well beyond both his tribal family and his lifetime. It was a promise of worldwide salvation to come.
Gal. 3:10
Cursed be every one -- A citation from Deut. 27:26. This is the final and climactic curse that Israel invoked upon itself in the oath ceremony that ratified the Deuteronomic covenant. In the subsequent context, Moses predicted the rebellion and cursing of Israel (Deut. 28:47-68) as well as the eventual restoration and blessing of Israel (Deut. 30:1-10). It is possible this passage was used by the Judaizers to insist on the necessity of circumcision, lest nonobservance of the Law result in a curse. Paul, however, uses it against them, charging that everyone who embraces the Law embraces the curse, for not even the Judaizers follow all of its demands to perfection (Gal. 6:13).
Book of the law: A technical term for the Book of Deuteronomy (Deut 29:21; 30:10), which was written on a scroll and placed beside the Ark of the Covenant (Deut. 31:26). Some read it with reference to the Mosaic Law more generally.
Gal. 3:11
He who through faith: A citation from Hab. 2:4. Habakkuk is assured that, despite the coming invasion of Judea by the Babylonians, the one who clings to the Lord in faith will be given the grace of protection and will survive the catastrophe. From this text Paul hails faith, not observance of the Law, as the foundation of justification (3:21-22; Rom. 1:17).
Gal. 3:12
He who does them: A citation from Lev. 18:5. Leviticus promises life to Israel for observing the Torah and shunning the sins of the Gentiles. Yet, as the recurring transgressions of Israel show (Neh. 9:29), the Mosaic Law did not come with the grace needed to keep it (Rom. 8:4). Paul may be interpreting this passage through the lens of Ezek 20:11, 13, 21, where the Prophet contrasts the Levitical promise of life given at Sinai with the Deuteronomic promises of curse and death issued on the plains of Moab (Ezek. 20:25-26).
Gal. 3:13
Cursed be every one: A citation from Deut. 21:23. This refers to the practice of hanging executed criminals on trees to avert the wrath of God (Num. 25:4; 2 Sam. 21:9). For Paul, Jesus bore the curses pressing down upon Israel when he mounted the Cross (Gal. 3:10). This act enabled the blessings of the Abrahamic covenant, held back for centuries because of the curse, to pour forth upon Israel and the world as a result (3:14). The Dead Sea Scrolls likewise associate crucifixion with the curse of Deut. 21:22-23.
Gal. 3:14
The blessing of Abraham: I.e., the Spirit, which is the messianic blessing revealed by the Prophets (Is. 44:3; Ezek. 36:26-27; Joel 2:28). The exact expression is from Gen. 28:4, where Isaac confers the blessing of Abraham upon his son Jacob. This shows that Isaac alone was the bearer of the Abrahamic blessing, not Ishmael or any other of Abrahams sons (Rom. 9:7-9). Paul will capitalize on the significance of this in Gal 3:16 and 4:28.
Gal. 3:15-18
The major premise of Pauls covenant theology in Galatians, namely, that Israels failure to keep the Mosaic covenant did not relieve God of his prior obligation to fulfill the Abrahamic covenant ratified centuries earlier. Since even human covenants are inviolable once they are ratified by oath, the covenant oath that God swore to Abraham is even more so (Gen. 22:16-18; Heb. 6:13-18). Not even the ratification of subsequent covenants under Moses could alter or annul Gods unconditional pledge to bless the world through Abrahams offspring. In effect, then, the Abrahamic covenant both precedes and supersedes the Mosaic covenant that came after it.
Gal. 3:15
Will: The term means testament or will in secular Greek usage but covenant in biblical Greek usage. Despite the translation, the biblical sense of covenant is probably intended here, since (1) Paul uses the term this way in his other writings (Rom. 9:4; 11:27; 2 Cor. 3:6, 14; Eph. 2:12), (2) he uses it this way elsewhere in Galatians (3:17; 4:24), and (3) it is a known fact that a will in Greco-Roman antiquity could be altered or even annulled after the death of the testator who drafted it, which is the very point Paul denies in this verse. For a similar translation issue in Hebrews see Hebrews 9.
Gal 3:16
And to his offspring: A reference to Gen. 22:18. Paul is alluding to the covenant oath that God swore to Abraham to bless all nations through Isaac and his descendants (Sir. 44:21). It is significant for Paul that Abrahams other son, Ishmael, was disinherited in the preceding chapter of Genesis and thus excluded from this covenant (Gen. 21:10-12). Thus, when Paul stresses that the word offspring is singular rather than plural, he is (1) alluding to the divine election of Isaac over Ishmael in the Genesis narrative (Gal 4:28-31; Rom. 9:7-8) and (2) implying that Isaac is a type of Christ, so that the act that elicits the promised blessing (the sacrifice of Isaac) prefigures the act that fulfills it (the sacrifice of Jesus).
Gal. 3:17
Four hundred and thirty years: The duration of Israels stay in Egypt before the Exodus (Ex. 12:40-41). Thus, the Abrahamic covenant, last confirmed with Jacob (Gen. 28:14), preceded the ratification of the Mosaic covenant by more than four centuries (Ex. 19-24).
Gal. 3:19
It was added: The Torah was inserted into history between the Abrahamic covenant and the New Covenant.
Because of: The Greek can indicate either the goal (for the sake of) or the cause (by reason of) for adding the Law. Paul may have both ideas in mind: the goal of the Law was to expose transgressions and heighten Israels awareness of sin (Rom. 3:20; 5:20; 7:7); the cause for adding the Law, at least the bulk of its sacrificial and ceremonial rites, was the rebellion of Israel during the Exodus period, particularly the golden calf transgression
Ordained by angels: Jewish tradition based on the Greek version of Deut. 33:2 held that Moses received the Torah from the hands of the angels (Acts 7:53; Heb. 2:2; Josephus, Antiquities 15, 136).
Gal. 3:20
An intermediary: Moses, who delivered the Torah to Israel (Ex. 20:18-22; Deut. 5:4-5). That the Mosaic covenant involved a mediator implied that more than one party was responsible for fulfilling the terms of the covenant God and Israel. The Abrahamic covenant, by contrast, was a unilateral arrangement, i.e., God alone swore an oath and assumed the responsibility of blessing the world through Abrahams offspring (Gen. 22:16-18).
God is one: The monotheistic creed of ancient Israel (Deut. 6:4).
Gal. 3:22
Consigned all things to sin: Scripture declares all peoples, Jews and Gentiles alike, prisoners of sin. Paul spells this out in Rom. 3:9-19 and Rom. 11:32.
Gal. 3:23
Kept under restraint: The mass of ethical, juridical, and ceremonial laws codified in the Torah was designed to keep Israel in temporary protective custody, lest it imitate the depravity of the Gentiles.
Gal. 3:27
Baptized into Christ: Baptism is the sacrament of faith (3:26) and the rite of Christian initiantion that replaces circumcision (Col. 2:11-12). It cleanse us of sin, joins us with Christ, and makes us righteous children of God (Acts 22:16; Tit. 3:5; 1 Pet. 3:21). Pauls description of this mystery reflects early liturgical practice where the newly baptized put on a white garment to symbolize their purity in Christ (Rom. 13:14; Eph 4:24).
Gal. 3:28
You are all one: All peoples, irrespective of ethnic, gender, and social distinctions, are equal candidates for salvation and sonship in Christ (Col. 3:11).
I hope this helps.
Heres more on the question of Will or Covenant:
Seventeen times the Letter to the Hebrews uses the Greek term diatheke, which is normally and rightly translated covenant. Most modern translations, however, make an exception for Heb. 9:16-17, where this same word is rendered either will or testament in two successive verses.
This shift in translation reflects an interpretive shift on the part of many scholars, who hold that the author of Hebrews jumps momentarily from a theological discussion about covenants to establish a legal analogy with last wills and testaments. The aim is to illustrate how the death of Jesus was necessary in order for Israel to receive its Christian inheritance. In support of this, scholars point out that in secular Greek, diatheke does indeed refer to a last will and testament. Moreover, it is said that a persons will, once documented in writing, had no legal force while the person who drafted it was still alive; only when he died would the terms and benefits of the will go into effect. This testamentary view, which interprets Heb. 9:16-17 against the backdrop of secular Hellenistic culture, represents the majority opinion among biblical scholars today.
There is reason to believe, however, that the author may be thinking of a covenant in these two verses and not a persons will. The literary context of Hebrews supports this, as does the historical context of testamentary practice in the New Testament period:
(1) Literary Context: Scholars are united in holding that every occurrence of diatheke in the Letter to the Hebrews, outside of these two disputed verses, refers to a covenant. No one doubts, in other words, that its author stands firmly within the stream of Jewish tradition represented by the Greek Septuagint, where diatheke is the standard translation for the Hebrew term berit, covenant. This is especially pronounced in Hebrews 8-9, where the author is drawing lines of comparison and contrast between the Old Covenant ratified under Moses and the New Covenant sealed by the blood of Jesus Christ. Since Heb. 9:16-17 is woven into the fabric of this discourse on covenant theology, there is every reason to believe that the author has a biblical background in mind when he speaks of a diatheke rather than a secular and Hellenistic one.
(2) Historical Context: Another strike against the testamentary reading of Heb 9:16-17 is that the authors statements do not correspond precisely to accepted legal practice. For instance, Hebrews insists that a diatheke is confirmed only at death; yet history is clear that a last will and testament was considered valid before death, that is, as soon as it was properly drafted, publicly witnessed, and officially notarized. Hebrews likewise contends that a diatheke is not in force as long as the one who made it is living; yet history again shows that sometimes a testamentary inheritance was distributed to beneficiaries while the testator who drafted it was still alive. This to makes it unlikely that the author of Hebrews is thinking of a will instead of a covenant in Heb. 9:16-17.
The real benefit of translating diatheke as covenant in Heb. 9:16-17 is that it makes superior sense of the theological point being made. In other words, these verses are meant to explain how the death fo Jesus redeemed Israel from its transgressions of the Mosaic covenant (Heb. 9:15) According to covenant practice in ancient Israel, parties who enter a covenant swear an oath that invokes the curse upon anyone who would dare to violated the covenant. This is precisely what Israel did at the foot of Mount Sinai when the nation entered its covenant with Yahweh. The ratification ceremony, which involved the slaying of oxen in a symbolic blood ritual, was a visible and tangible sign of the oath curse, signifying that Israel chose to accept the same deadly fate should it transgress the covenant (Ex. 24:1-8; Heb. 9:18-20). In other words, the animals slain by the covenant maker signified the curse of death that God would impose on the covenant breaker. Thus, as soon as Israel betrayed the covenant at Sinai, falling down in worship before the golden calf (Ex. 32:1-6), the nation placed itself under the curse of death (Ex. 32:27-28). However, instead of activating the full force of the curse then and there, God mercifully allowed Israel to live (Ex. 32:30-34) and instituted the annual Day of Atonement (Lev. 16:1-34) to hold the curse of death an bay until such time as he would deal with the transgressions of his people in a definitive way (Heb. 9:24-26).
Understood in these terms, the crucial text in Heb. 9:16-17 refers directly and specifically to the Sinai covenant and may be paraphrased as follows: Where there is a covenant (like the one made at Sinai), the death of the (unfaithful) covenant partner must be endured (once it is broken). For a covenant is confirmed (as being in effect) when death occurs, since it is never in force when the (guilty) covenant partner is living. The author is thus explaining how Israel, despite being guilty of transgressing the Mosaic covenant, was spared the curse of national death it had invoked upon itself. Instead, Jesus took this curse upon himself, finally putting the sanctions of the Mosaic covenant into full effect and bringing it all to an end (Heb. 9:15). This is the atonement theology of the Letter to the Hebrew, which is a covenant theology through and through. It shows us that Christ gave consent to death, not only to seal a new diatheke with the world, but to deal with the unfinished business of the old diatheke broken by Israel.
All of this is taken from Dr. Scott Hahn, who wrote the book, "Kinship By Covenant: A Canonical Approach to the Fulfillment of God's Saving Promises" He is also one of the most respected biblical theologian in the world.
Please read this fully. If you haven't read about covenants and covenant theology, then pick up a good book. I hope this helps.
God bless and Shabbat Shalom,
