A Filter, A Lens, and A Prism: Three Ways Christ Applies the Law of Moses to New Covenant Disciples


One of the most challenging aspects of reading the Bible is applying the old covenant law to the new covenant follower of Christ. As the book Five Views on Law and Gospel illustrates, there are multiple ways in which Christians have sought to apply the Old Testament and its legal demands to the church today. And one of the most familiar ways is to differentiate three parts of the law.

Typically divided as moral, civil, and ceremonial, the tripartite approach to the Old Testament argues that some laws are eternal and unchanging (the moral); others are related to the theocracy given to  Israel (the civil); still others are related to the system of priests, sacrifices, and the temple (the ceremonial). In Christ, the civil and ceremonial came to their completion, while the moral law continues unabated.

The trouble with this approach is that the Old Testament never specifies the tripartite division and in many places the moral, civil, and ceremonial overlap. Still, we must make some sense of the way parts of the law continue and others do not. And historically, the tripartite division has a long tradition of helping Christians think carefully about the Bible, the Law, and the Gospel. Still, it is not the only way and there may be better approaches.

Addressing this subject, I have found help in the way Jonathan Lunde uses three images to describe the way in which Christ fulfills the law. In his book Following Jesus, the Servant Kinghe spends three chapters outlining the way Christ fulfills the law of Moses. Focusing much of his attention on the Sermon on the Mount, he specifies the way Christ functions as filter, lens, and prism. In some ways, Christ brings the laws of Moses to an end (filter); in others, he clarifies what the law already meant (lens); and still in other ways, he heightens the demands of the law (prism).

While these three approaches (filter, lens, prism) are extra-textual and only illustrative, I find them more helpful in getting at what the text says. They make us consider what Jesus does and does not say about the law. And instead of foisting an extra-textual grid on the Bible, like the tripartite division of the law, they make us listen closely to the text itself to see how Jesus mediates between old and new covenants.

Because this approach is explicitly Christ-centered, in a way that the tripartite division of the law is not, I find it to be a surer guide. Likewise, because it does not create a whole system of categorization (which the Bible does not have), it lets the text of Scripture speak. It also permits more freedom to disagree about certain points—as I do below in two ways—and helps us go back to the feet of Jesus to learn how he approaches the old and new covenants.

Jesus as the Filter

Citing animal sacrifices, food laws, circumcision, and Moses hard-hearted allowance for divorce, Lunde explains how Jesus as a filter brings many old covenant laws to an end.

In his role as ‘filter,’ Jesus brings certain elements of the law to their culmination, thereby rendering their ongoing observance covenantally improper. Accordingly, Jesus’ fulfillment brings to an end the Old Testament sacrifices, food laws, circumcision, and largely even Moses provision for divorce. It is significant that when Jesus abrogates these aspects of the law, the result is not a lowering of the law’s demand of righteousness. In fact, the opposite is true. What continues on in each case is a summons to a life of righteousness befitting the New Covenant era, to which each superseded element was pointing all along. For this reason, it is appropriate that disciples of Jesus continue to reflect on these Old Testament realities, allowing their obsolescence to remind them of the righteousness that God expects from his Spirit-filled, New Covenant people. (139–40)

Jesus as the Lens

Focusing on Moses chief commands to love God and neighbor, Lunde shows how Jesus clarifies God’s desire for love, mercy, and truth.

Jesus’ summation of the law here amounts to bringing its core teachings into focus. As such, Jesus is functioning as the “lens” to recover the law’s original intention. He is not changing anything in the law, though he may be interacting with competing views that people at that time were defending concerning the question of the law’s weightiest commands. (142)

As if he were turning the focus wheel, Jesus brings several of the law’s command, back into clarity, dispensing with various traditions that had obscured the view. Most fundamentally, Jesus identifies as the heart of the law an all-consuming love for God and a love for our neighbors that is commensurate with our own self-love (Matt. 22:34–40). Lacking these, no efforts to obey the law will be successful. Accordingly, Jesus confronts traditional conceptions of purity that inhibit the merciful pursuit of others (9:9-13). He explodes culturally and racially defined limitations on what it means to be compassionate toward another (Luke 10:25–37). He recovers the heart of the Sabbath and illustrates how its provision leads to mercy toward others (Luke 13:10–17). And he restores the law’s straightforward demand of truthfulness from God’s people (Matt. 5:33–37). (152)

Lunde includes Sabbath in this list, but I would approach that subject differently, as I understand Sabbath as a sign of the old covenant more than a eternal law for creation. For more on that subject see From Sabbath to Lord’s Day.

Jesus as the Prism

Finally, Lunde suggests that the murder prohibition (Matt 5:21–26), the adultery prohibition (Matt 5:27–30), and the justice provision (Matt 5:38–42) are elevated by the coming of Christ.

A prism refracts, or bends, light. Consequently, light coming out the other side of a prism will be moving in a slightly different direction than when it entered. In the process, white light is refracted into its different frequencies, allowing the colors of the spectrum normally hidden from view to be seen in their distinctive beauty. When I speak of Jesus’ role as “prism,” I am referring to his “refraction” of the law into the New Covenant era, occasionally raising its demand and displaying its inherent beauty.  As the King who reigns over the people of the New Covenant, Jesus demands the heightened righteousness befitting the era in which the covenants have come to their fulfillment. In the process, Jesus brings out the colorful panoply of the laws ultimate intentions, now in its new covenant expression. (154–55)

As the “prism” in relation to the Old Testament law, Jesus refracts its commands to new levels of demand, displaying in the process the glory of God’s ultimate desire for his people. Accordingly, his disciples are not to allow relational anger to run interference with the command to love others. Rather, they are to pursue reconciliation passionately and intentionally. Similarly, they are to remain sexually pure, resisting even the temptation of entertaining another in one’s thoughts for the purpose of sexual arousal. . . . In the end, it is obvious that Jesus call to this transcending obedience amounts to the end-time expression of God’s demand of obedience encapsulated in Abrahams mountaintop test and the law’s overall summons. Jesus’ teachings here make it clear that God is still seeking people who will reflect his character in the costliest of ways, so that others might indeed perceive who he is. (165)

In my estimation, Jesus words in the Sermon on the Mount do not elevate the law (regarding murder, adultery, and love), so much as they elevate the disciple to do what the law demands. As we learn in Scripture, the problem with the old covenant was not the measure of the law (see Rom 7:12); the problem was the weakness of the flesh (8:1–3). Under the old covenant, God spoke to the heart and called for Israel to circumcise their hearts (Deut 10:16); the tenth commandment takes aim at the heart, as does every other command. It is wrong to say, God only focused on the externals with Israel, and that Jesus was elevating the law.

Rather, what Jesus does is to clarify the law (lens) and circumcise the heart with his Spirit such that elevated disciples will desire to obey God’s commandment. In his way, Jesus’ work as a prism is less in elevating the law above the law, but in elevating (read: raising to life) disciples who will do what the law required. This is exactly what the Prophets promised as they looked ahead to the new covenant (see Jer 31:33; Ezek 36:26–27).

In this way, Christ’s prism work refracts the light of God into the believers heart. This is not how Lunde puts it in his chapter, but I believe it is more true to the text of New Testament and the designs of the new covenant. And in this way, Lunde’s illustration still stands even if it needs some tweaking of its own.

With the Law Written on Our Hearts: The Great Gift of the New Covenant

All in all, Lunde’s three approaches to Jesus, the law, and the new covenant believer are immensely helpful. They give a clear illustration of how Jesus fulfills and transforms the old covenant into the new, without making a final decision about any system of categorization. Moreover, they show how important Christ is for disciples to walk in holiness and how he both completes and continues the Old Testament Scriptures.

Indeed, since Adam’s fall mankind has never been able to walk in holiness on our own. But now in Christ, holiness is attainable—positionally and experientially.  With the law written on our hearts, we can grow in holiness and in intimacy with our heavenly Father. This is the good news of the new covenant—not that God has swept his law away, but in Christ he has forgiven us for breaking the law and has now, by his Spirit, given us power to do all he has commanded.

Part of that new covenant discipleship is learning how to read Scripture and apply it to our lives. And on that point, these three illustrations are helpful.

Soli Deo Gloria, ds

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  1. Pingback: The Good News of the Law (1 Timothy 1:8–11) | Via Emmaus

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