A superficial reading of the New Testament reveals clearly that the faith of the first Christians in Jesus was integrated with their understanding of their Scriptures-- the Old Testament. Although many continue to do so, there is no responsible interpretation of the New Testament that pits Old against New, law against grace, or embraces Spirit apart from law.
In the Gospel of Matthew, Jesus says,
‘Do not think that I have come to abolish the law or the prophets; I have come not to abolish but to fulfill. For truly I tell you, until heaven and earth pass away, not one letter, not one stroke of a letter, will pass from the law until all is accomplished. Therefore, whoever breaks one of the least of these commandments, and teaches others to do the same, will be called least in the kingdom of heaven; but whoever does them and teaches them will be called great in the kingdom of heaven (5:17-19).
The first thing Jesus says is that he has not abolished the law or the prophets. It is important to emphasize the two together. It has become a standard shibboleth in some mainline and evangelical circles today to pit the prophets against the law as if the two are antithetical. Once in conversation with a fellow pastor about biblical interpretation he said to me in response to a point I had just made, "But that's the law, not the prophets." Such a statement would have made no sense to Jesus.
New Testament scholar, Richard Hays(1) helps illuminate Jesus' perspective on Torah obedience.
First, "Jesus demands a higher righteousness that includes obedience to the Torah." Here in view is Jeremiah 31:31-34 where the law is engraved on the human heart. Torah obedience is not done because one has to obey, but because one wants to obey. John Wesley referred to holiness as our loving response to God's love for us.
Second, "Matthew insists that the commandments of the law remain fully in force. Jesus, rather than abolishing the law, calls his followers to a higher righteousness that exceeds, rather than negates, the righteousness of the scribes and Pharisees." This, as we shall see, is a little tricky when we get to St. Paul, who argues that certain aspects of the law should not be forced upon the Gentiles; but it suffices for the moment that what Jesus has in mind is the intensification of the law, not its relaxation. One does not have to commit murder to be guilty of it. One does not have to commit adultery to be guilty of it. In actuality, Jesus has a more rigorous view of the law than the scribes and Pharisees.
Third, "the story of Israel is carried forward by a community of discipleship, as envisioned in the Sermon on the Mount, a community that embodies radical obedience to the Torah as authoritatively interpreted by Jesus." Notice that last phrase, "as interpreted by Jesus." Jesus is the hermeneutical lens, through which Scripture is read. When Jesus states, "You have heard it said... but I say to you" (e.g. Matthew 5:21-22) he is not abrogating the commandments, he is intensifying their force in the context of rigorous discipleship. Whereas Mark's Jesus reminds the Pharisees that "the sabbath was made for humankind, and not humankind for the sabbath" (Mark 2:27), Matthew's Jesus sees sabbath regulations through a Christological lens-- "the Son of Man is lord of the sabbath" (Matthew 12:8).
Fourth, "that Matthew seriously believes that not a jot or a tittle shall perish from the law (5:18) is nowhere made clearer than in Jesus' scathing attack on the scribes and Pharisees in Matthew 23." In this chapter, once again Jesus does not reject Torah obedience, but desires to refocus it as he says to the religious leaders:
Woe to you, scribes and Pharisees, hypocrites! For you tithe mint, dill, and cummin, and have neglected the weightier matters of the law: justice and mercy and faith. It is these you ought to have practiced without neglecting the others. You blind guides! You strain out a gnat but swallow a camel! (Mathew 23:23-24)
For Jesus, the problem with the Pharisees is not that they obey the law, but that they don't. They have been so caught up in the minutiae of its regulations only, that they miss the bigger picture of the purpose of the law. Scot McKnight says that while the Pharisees preached the love of Torah, Jesus preached the Torah of love(2). Unfortunately, some have interpreted the latter as promoting moral laxity in favor of a shallowly sentimental notion of love, whereas for Jesus the Torah of love was a call to radical obedience and sacrificial discipleship with an intensified interpretation of the law.
Hays summarizes the discussion succinctly-- "Matthew is a good holiness theologian: he teaches that Jesus' followers must carry forward the story of Israel within a community of great moral stringency, in strict obedience to the commandments of Torah."
Hays also rightly notes that the fulfillment of the law does seem to exclude certain food and purity regulations (Matthew 15:10-20), but as we shall see when we get to Paul, the moral law of the Torah remains in force. Both Jesus and Paul indicate that those aspects of the law that emphasize ethnically ritual practices are fulfilled in their end, but those regulations are few and far between.
(1) Richard Hays, Echoes of Scripture in the Gospels.
(2) Scot McKnight, The King Jesus Gospel: The Original Good News Revisited.