A well-known author in a new book has proposed a dangerous theology in which the Old Testament, by the author's own words, is not as authoritative as the New and is essentially unnecessary for our lives as Christians, for we learn everything we need to know from the Gospels and from the apostles and early church. The OT might be occasionally fun to read and perhaps mildly informative, but it's not entirely necessary and so, if we ever want to recapture the essence of our Christian faith, it starts with ditching the story of Israel.
Aside from being directly contradictory to what Jesus Himself says about the Old Testament and the old covenant, this dangerous theology strips Jesus and Christianity of all of its meaning. The truth is that without the OT, we cannot possibly begin to understand what Jesus was all about, and we make Him nothing more than a crazy man.
For example, the author argues that we no longer sacrifice animals. We're not required to. Therefore, all of that Temple worship stuff is completely unnecessary to our Christian faith. We don't need to know about lambs and rams and goats because they are not part of the faith story that we're telling.
On the surface, that's true. I've never seen a single worshiper walk into the church with a live animal offering to God. (We had someone bring a skunk once, but not to sacrifice.) But it should not escape anyone's sight that Jesus Himself has become our offering, and if we do not understand what it meant to bring a lamb to God for the fellowship and the atonement of sins and the easing of guilt and the cleansing of impurity, then we cannot begin to fathom what it means when the Lamb says He sacrificed Himself for us. Without the Old Testament framework, He's simply gone crazy. What is a sacrifice? Why would He die for us? That doesn't make any sense. Unless you have Temple worship. Unless you know what the sacrifice means.
Or take what Peter tells us in his testimony. He calls us a "chosen people, a royal priesthood, a holy nation, God's special possession" (1 Peter 2:9). There are only two ways to understand these descriptions - either they are rooted deeply in the OT and the developing story of God since in the beginning or they are terms that Peter has appropriated from the culture-at-large to make a point about the role that he sees Christians playing in their world. If he's appropriating something, he's essentially copying it, and he's modeling the Christian faith off of the world.
But if these terms come from the story that God's been telling all along, then they become something deeply holy and sacred. And, in fact, that's what they are. We know what "a chosen people" means because we have the testimony, in the OT, of God choosing a people - through Noah, Abraham, Isaac, Jacob, Moses, Israel, over and over and over again. We know what a "priesthood" is because we have the instructions for and examples of the office of the priest. We understand the royalty of it because of Israel's kings and her hope for a coming, promised King. We know what a "holy" nation is because God's law was centered on making His people holy unto Him. We have in our hands the story of God's "special possession," and this means that when Peter tells us that's who we are, we can know what that means.
As long as we have the Old Testament to tell us.
Or here's one - Jesus says that what's important to Him is that the people would come to know not Him, but the Father who sent Him. The Old Testament is the story of the Father; it's a revelation of God the Father. In fact, a couple of points must be made here. First, we understand Jesus the Son only because of what we know of God the Father. If we didn't know God, we wouldn't be able to recognize what is holy in Jesus or to comprehend the connection between the two of them. Jesus might be a good guy, a smart guy, a wise teacher, but He'd also be a lunatic. Without the revelation of God, we have no framework for Jesus at all.
It also must be said that Jesus wants us to know the Father, but the Father is not revealed in the New Testament. None of the authors spend any time talking about Him. Jesus speaks of the Father frequently, but always as if the Father is already knowable and, perhaps, known. How could the Father already be knowable if we don't have or need a testimony about Him? He can't. We need the Old Testament to do exactly what Jesus wants us to do, to know the Father who sent Him.
Again and again, our Christian faith depends upon the witness of the Old Testament. Without it, there is simply no way to make sense of who we are supposed to be, how we are supposed to live, what any of this means. To say that because Jesus came, we no longer need it, is a dangerous, ridiculous theology that sets us all about following a crazy man instead of continuing to live out the deeply rooted and developing story of God in our world. And it's just plain wrong.
So is the Old Testament as authoritative as the New? You bet it is. Because it's still the story we're living, just a different chapter of it.