The article “Overview of the Bible” in the beginning of the ESV Study Bible is excellent.
Overview of the Bible: A Survey of the History of Salvation
How does the Bible as a whole fit together? The events recorded in the Bible took place over a span of thousands of years and in several different cultural settings. What is their unifying thread?
One unifying thread in the Bible is its divine authorship. Every book of the Bible is God’s word. The events recorded in the Bible are there because God wanted them recorded, and he had them recorded with his people and their instruction in mind: “For whatever was written in former days was written for our instruction, that through endurance and through the encouragement of the Scriptures we might have hope” (Rom. 15:4).
God’s Plan for History
The Bible also makes it clear that God has a unified plan for all of history. His ultimate purpose, “a plan for the fullness of time,” is “to unite all things in him [Christ], things in heaven and things on earth” (Eph. 1:10), “to the praise of his glory” (Eph. 1:12). God had this plan even from the beginning: “remember the former things of old; for I am God, and there is no other; I am God, and there is none like me, declaring the end from the beginning and from ancient times things not yet done, saying, ‘My counsel shall stand, and I will accomplish all my purpose’” (Isa. 46:9–10). “When the fullness of time had come,” when the moment was appropriate in God’s plan, “God sent forth his Son, born of woman, born under the law, to redeem those who were under the law” (Gal. 4:4–5).
The work of Christ on earth, and especially his crucifixion and resurrection, is the climax of history; it is the great turning point at which God actually accomplished the salvation toward which history had been moving throughout the OT. The present era looks back on Christ’s completed work but also looks forward to the consummation of his work when Christ will come again and when there will appear “new heavens and a new earth in which righteousness dwells” (2 Pet. 3:13; see Rev. 21:1–22:5).
The unity of God’s plan makes it appropriate for him to include promises and predictions at earlier points in time, and then for the fulfillments of these to come at later points. Sometimes the promises take explicit form, as when God promises the coming of the Messiah, the great Savior whom Israel expected (Isa. 9:6–7). Sometimes the promises take symbolic form, as when God commanded animal sacrifices to be offered as a symbol for the forgiveness of sins (Leviticus 4). In themselves, the animal sacrifices were not able to remove sins permanently and to atone for them permanently (Heb. 10:1–18). They pointed forward to Christ, who is the final and complete sacrifice for sins.
Christ in the Old Testament
Since God’s plan focuses on Christ and his glory (Eph. 1:10), it is natural that the promises of God and the symbols in the OT all point forward to him. “For all the promises of God find their Yes in him [Christ]” (2 Cor. 1:20). When Christ appeared to the disciples after his resurrection, his teaching focused on leading them to understand how the OT pointed to him: “And he said to them, ‘O foolish ones, and slow of heart to believe all that the prophets have spoken! Was it not necessary that the Christ should suffer these things and enter into his glory?’ And beginning with Moses and all the Prophets, he interpreted to them in all the Scriptures the things concerning himself” (Luke 24:25–27). One could also look at Luke 24:44–48: “Then he said to them, ‘These are my words that I spoke to you while I was still with you, that everything written about me in the Law of Moses and the Prophets and the Psalms must be fulfilled.’ Then he opened their minds to understand the Scriptures, and said to them, ‘Thus it is written, that the Christ should suffer and on the third day rise from the dead, and that repentance and forgiveness of sins should be proclaimed in his name to all nations, beginning from Jerusalem. You are witnesses of these things.’”
When the Bible says that “he opened their minds to understand the Scriptures” (Luke 24:45), it cannot mean just a few scattered predictions about the Messiah. It means the OT as a whole, encompassing all three of the major divisions of the OT that the Jews traditionally recognized. “The Law of Moses” includes Genesis to Deuteronomy. “The Prophets” include both the “former prophets” (the historical books Joshua, Judges, 1–2 Samuel, and 1–2 Kings) and the “latter prophets” (Isaiah, Jeremiah, Ezekiel, Daniel, and the 12 Minor Prophets, Hosea–Malachi). “The Psalms” is representative of the third grouping by the Jews, called the “Writings.” At the heart of understanding all these OT books is the truth that they point forward to the suffering of Christ, his resurrection, and the subsequent spread of the gospel to “all nations” (Luke 24:47). The OT as a whole, through its promises, its symbols, and its pictures of salvation, looks forward to the actual accomplishment of salvation that took place once-for-all in the life, death, and resurrection of Jesus Christ.
The Promises of God
In what ways does the OT look forward to Christ? First, it directly points forward through promises of salvation and promises concerning God’s commitment to his people. God gave some specific promises in the OT relating to the coming of Christ as the Messiah, the Savior in the line of David. Through the prophet Micah, God promises that the Messiah is to be born in Bethlehem, the city of David (Mic. 5:2), a prophecy strikingly fulfilled in the NT (Matt. 2:1–12). But God often gives more general promises concerning a future great day of salvation, without spelling out all the details of how he will accomplish it (e.g., Isa. 25:6–9; 60:1–7). Sometimes he promises simply to be their God (see Gen. 17:7).
One common refrain is that, “I will be their God, and they shall be my people” (cf. Jer. 31:33; Hos. 2:23; Zech. 8:8; 13:9; Heb. 8:10). Variations on this broad theme may sometimes focus more on the people and what they will be, while at other times they focus on God and what he will do. God’s promise to “be their God” is really his comprehensive commitment to be with his people, to care for them, to discipline them, to protect them, to supply their needs, and to have a personal relationship with them. If that commitment continues, it promises to result ultimately in the final salvation that God works out in Christ.
The principle extends to all the promises in the OT. “For all the promises of God find their Yes in him [Christ]” (2 Cor. 1:20). Sometimes God gives immediate, temporal blessings. These blessings are only a foretaste of the rich, eternal blessings that come through Christ: “Blessed be the God and Father of our Lord Jesus Christ, who has blessed us in Christ with every spiritual blessing in the heavenly places” (Eph. 1:3).
Warnings and Curses
God’s relation to people includes not only blessings but also warnings, threatenings, and cursings. These are appropriate because of God’s righteous reaction to sin. They anticipate and point forward to Christ in two distinct ways. First, Christ is the Lamb of God, the sin-bearer (John 1:29; 1 Pet. 2:24). He was innocent of sin, but became sin for us and bore the curse of God on the cross (2 Cor. 5:21; Gal. 3:13). Every instance of the wrath of God against sin, and his punishments of sin, looks forward to the wrath that was poured out on Christ on the cross.
Second, Christ at his second coming wars against sin and exterminates it. The second coming and the consummation are the time when the final judgment against sin is executed. All earlier judgments against sin anticipate the final judgment. Christ during his earthly life anticipated this final judgment when he cast out demons and when he denounced the sins of the religious leaders.
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).
It is worthwhile to focus on one specific element in OT covenants, namely, the promise concerning offspring. In making a covenant with Abram, God calls on him to “walk before me, and be blameless” (Gen. 17:1). That is a human obligation in the covenant. On the divine side, God promises that he will make Abram “the father of a multitude of nations” (Gen. 17:4), and he renames him Abraham (Gen. 17:5). The covenant with Abraham in fact extends beyond Abraham to his posterity: “And I will establish my covenant between me and you and your offspring after you throughout their generations for an everlasting covenant, to be God to you and to your offspring after you. And I will give to you and to your offspring after you the land of your sojournings, all the land of Canaan, for an everlasting possession, and I will be their God” (Gen. 17:7–8).
The promises made to Abraham are exceedingly important within the OT because they are the foundation for the nation of Israel. The history after Abraham shows that Abraham had a son, Isaac, in fulfillment of God’s promise to Sarah. Isaac was the immediate result of God’s promise of offspring who will inherit the land. Isaac in turn had a son, Jacob, and Jacob was the father of 12 sons who in turn multiplied into the 12 tribes of Israel. The nation of Israel became the next stage in the offspring that God promised.
But how does this relate to Christ? Christ is the descendant of David and of Abraham, as the genealogy in Matthew indicates (Matt. 1:1). Christ is the offspring of Abraham. In fact, he is the offspring in a uniquely emphatic sense: “Now the promises were made to Abraham and to his offspring. It does not say, ‘And to offsprings,’ referring to many, but referring to one, ‘And to your offspring,’ who is Christ” (Gal. 3:16; see notes on Gen. 22:15–18).
Abraham was told to “walk before me, and be blameless” (Gen. 17:1). Abraham was basically a man of faith who trusted God (Gal. 3:9; Heb. 11:8–12, 17–19). But Abraham also had his failures and sins. Who will walk before God and be blameless in an ultimate way? Not Abraham. Not anyone else on earth either, except Christ himself (Heb. 4:15). All the other candidates for being “offspring” of Abraham ultimately fail to be blameless. Thus the covenant with Abraham has an unbreakable tie to Christ. Christ is the ultimate offspring to whom the other offspring all point. One may go down the list of offspring: Isaac, Jacob, then the sons of Jacob. Among these sons, Judah is their leader who will have kingship (Gen. 49:10). David is the descendant of Abraham and Judah; Solomon is the descendant of David; and then comes Rehoboam and the others who descend from David and Solomon (Matt. 1:1–16).
Christ is not only the descendant of all of them by legal right; he is also superior to all of them as the uniquely blameless offspring. Through Christ believers are united to him and thereby themselves become “Abraham’s offspring” (Gal. 3:29). Believers, Jews and Gentiles alike, become heirs to the promises of God made to Abraham and his offspring: “There is neither Jew nor Greek, there is neither slave nor free, there is no male and female, for you are all one in Christ Jesus. And if you are Christ’s, then you are Abraham’s offspring, heirs according to promise” (Gal. 3:28–29).
Christ as the Last Adam
Christ is not only the offspring of Abraham, but—reaching back farther in time to an earlier promise of God—the offspring of the woman: “I will put enmity between you [the serpent] and the woman, and between your offspring and her offspring; he shall bruise your head, and you shall bruise his heel” (Gen. 3:15). The conquest over the serpent, and therefore the conquest of evil and the reversal of its effects, is to take place through the offspring of the woman. One can trace this offspring down from Eve through Seth and his godly descendants, through Noah, and down to Abraham, where God’s promise takes the specific form of offspring for Abraham (see Luke 3:23–38, which traces Jesus’ genealogy all the way back to Adam). Thus Christ is not only the offspring of Abraham but the last Adam (1 Cor. 15:45–49). Like Adam, he represents all who belong to him. And he reverses the effects of Adam’s fall.
Shadows, Prefigures, and “Types”
The NT constantly talks about Christ and the salvation that he has brought. That is obvious. What is not so obvious is that the same is true of the OT, though it does this by way of anticipation. It gives us “shadows” and “types” of the things that were to come (see 1 Cor. 10:6, 11; Heb. 8:5).
For example, 1 Corinthians 10:6 indicates that the events the Israelites experienced in the wilderness were “examples for us.” And 1 Corinthians 10:11 says, “Now these things happened to them as an example, but they were written down for our instruction, on whom the end of the ages has come.” In 1 Corinthians 10:6 and 11, the Greek word for “example” is typos, from which derives the English word “type” (cf. Rom. 5:14).
A “type,” in the language of theology, is a special example, symbol, or picture that God designed beforehand, and that he placed in history at an earlier point in time in order to point forward to a later, larger fulfillment. Animal sacrifices in the OT prefigure the final sacrifice of Christ. So these animal sacrifices were “types” of Christ. The temple, as a dwelling place for God, prefigured Christ, who is the final “dwelling place” of God, and through whom God comes to be with his people (Matt. 1:23; John 2:21). The OT priests were types of Christ, who is the final high priest (Heb. 7:11–8:7).
Fulfillment takes place preeminently in Christ (Eph. 1:10; 2 Cor. 1:20). But in the NT those people who are “in Christ,” who place their trust in him and experience fellowship with his person and his blessings, receive the benefits of what he has accomplished, and therefore one can also find anticipations or “types” in the OT that point forward to the NT church, the people in the NT who belong to Christ. For example, the OT temple not only prefigured Christ, whose body is the temple (John 2:21), but prefigured the church, which is also called a temple (1 Cor. 3:16–17), because it is indwelt by the Holy Spirit. Some OT symbols also may point forward especially to the consummation of salvation that takes place in the new heaven and the new earth yet to come (2 Pet. 3:13; Rev. 21:1–22:5). Old Testament Jerusalem prefigured the new Jerusalem that will come “down out of heaven from God” (Rev. 21:2).
Christ the Mediator
The Bible makes it clear that ever since the fall of Adam into sin, sin and its consequences have been the pervasive problem of the human race. It is a constant theme running through the Bible. Sin is rebellion against God, and it deserves death: “the wages of sin is death” (Rom. 6:23). God is holy, and no sinful human being, not even a great man like Moses, can stand in the presence of God without dying: “you cannot see my face, for man shall not see me and live” (Ex. 33:20). Sinful man needs a mediator who will approach God on his behalf. Christ, who is both God and man, and who is innocent of sin, is the only one who can serve: “there is one mediator between God and men, the man Christ Jesus, who gave himself as a ransom for all” (1 Tim. 2:5–6).
Though there is only one mediator in an ultimate sense, in a subordinate way various people in the OT serve in some kind of mediatorial capacity. Moses is one of them. He went up to Mount Sinai to meet God while all the people waited at the bottom of the mountain (Exodus 19). When the people of Israel were terrified at hearing God’s audible voice from the mountain, they asked for Moses to bring them God’s words from then on (Ex. 20:18–21). God approved of the arrangement involving Moses bringing his words to the people (Deut. 5:28–33).
But if there is only one mediator, as 1 Timothy 2:5 says, how could Moses possibly serve in that way? Moses was not the ultimate mediator, but he prefigured Christ’s mediation. Because Moses was sinful, he could not possibly have survived the presence of God without forgiveness, that is, without having a sinless mediator on his own behalf. God welcomed Moses into his presence only because, according to the plan of God, Christ was to come and make atonement for Moses. The benefits of Christ’s work were reckoned beforehand for Moses’ benefit. And so it must have been for all the OT saints. How could they have been saved otherwise? God is perfectly holy, and they all needed perfection. Perfection was graciously reckoned to them because of Christ, who was to come.
That means that there is only one way of salvation, throughout the OT as well as in the NT. Only Christ can save us. “And there is salvation in no one else, for there is no other name under heaven given among men by which we must be saved” (Acts 4:12). The instances of salvation in the OT all depend on Christ. And in the OT, salvation frequently comes through a mediator, a person or institution that stands between God and man. All the small instances of mediation in the OT prefigure Christ. How else could it be, since there is only one mediator and one way of salvation?
So understanding of the unity of the Bible increases when one pays attention to instances where God brings salvation, and instances where a mediator stands between God and man. These instances include not only cases where God brings spiritual salvation in the form of personal fellowship, spiritual intimacy, and the promise of eternal life with God. They also include instances of temporal, external deliverance—”salvation” in a physical sense, which prefigures salvation in a spiritual sense. And indeed, salvation is not merely spiritual. Christians look forward to the resurrection of the body and to “new heavens and a new earth in which righteousness dwells” (2 Pet. 3:13). Personal salvation starts with renewal of the heart, but in the end it will be comprehensive and cosmic in scope. The OT, when it pays attention to physical land and physical prosperity and physical health, anticipates the physicality of the believer’s prosperity in the new heavens and the new earth.
Instances of mediators in the OT include prophets, kings, and priests. Prophets bring the word of God from God to the people. Kings, when they submit to God, bring God’s rule to bear on the people. Priests represent the people in coming before God’s presence. Christ is the final prophet, king, and priest who fulfills all three functions in a final way (Heb. 1:1–3). One can also look at wise men, who bring God’s wisdom to others; warriors, who bring God’s deliverance from enemies; and singers, who bring praise to God on behalf of the people and speak of the character of God to the people.
Mediation occurs not only through human figures, but through institutions. Covenants play a mediatorial role in bringing God’s word to the people. The temple brings God’s presence to the people. The animal sacrifices bring God’s forgiveness to the people. In reading the Bible one should look for ways in which God brings his word and his presence to people through means that he establishes. All these means perform a kind of mediatorial role, and because there is only one mediator, it is clear that they all point to Christ.