What’s New in the New Covenant?

The prophets promised a new covenant for God’s people, and Jesus announced its arrival. But what change did this new covenant bring? Today, Sinclair Ferguson expounds on the glory that has come to us in the coming of Christ.

Welcome to Friday’s edition of Things Unseen. All this week, we’ve been reflecting in various ways on the topic of God’s covenant and especially His covenant of grace—the covenant that stretches back into Genesis 3:15, and then all the way forwards until the Lord Jesus Christ, who is Himself God’s covenant.

Now, whole books have been written on the covenant, and all we’ve been trying to do this week is to see in one or two ways that God’s covenant of grace unfolds in a series of covenants from start to finish. They all have their distinct shape and style, but they’re all the unfolding of one single promise. And I think what becomes clear to us is that in all of these different covenants, grace is the foundation for our response of unreserved, total, joyful obedience to the Lord.

Sometimes He gives us great details about what we are to do, as for example in the Mosaic administration. Sometimes He gives us principles, as in the Ten Commandments, that are carried over into the new covenant. He binds us to Himself so that we’ll become like Him and reflect His character in our lives—in other words, so that we’ll become more and more like the Lord Jesus, because doesn’t Paul say that God has predestined us to be conformed to the image of His Son? That’s what He has in view in making His covenants with us.

So, what makes the new covenant so new? It’s not that it presents a different way of salvation from the old covenant—we’ve seen that. It’s new in the sense that it fulfills everything that was promised in the earlier covenants God made. It’s new in the sense that when it comes, it makes all previous covenants seem old. Of course, the great promise about the new covenant is found in Jeremiah 31:31–34, a passage that’s referred to in several occasions in the New Testament, not least by Jesus Himself when He inaugurated the Lord’s Supper and said, “This is the new covenant in my blood.”

But I want us to notice two features of this promise given through Jeremiah. The first is that God promises a special location for His law. In the old covenant, it was placed inside the ark of the covenant. In the New Covenant, Jeremiah says, it’ll be written within the hearts of God’s people. What does that mean? Well, it’s the law that’s written in our hearts, so it doesn’t mean that the law changes, the Ten Commandments. Rather, what God is saying is that through the Spirit’s ministry, what was written originally into Adam’s heart—the instinct, the desire, the power to live in fellowship with God—that will be rewritten into the hearts of believers. The law itself—the law that was hidden in the ark of the covenant—couldn’t do that. And Paul makes that point in Romans 8:3–4. He says there that the Spirit, working within us, accomplished what the written law couldn’t do because of our sinfulness. And the result is that the righteous requirements of the law begin to be fulfilled in us as we walk according to the Spirit.

The second feature is this: in the new covenant, God says, “It won’t be necessary for a neighbor or brother to say to us, ‘Know the Lord,’ because we’ll all know the Lord.” Now, what can that mean? Well, it doesn’t mean that in the old covenant, the Lord wasn’t known, whereas He is in the new. After all, the same Jeremiah speaks about people knowing God in the Old Testament days. So, what it means here is that in the old covenant, there was a sense in which the knowledge of God came to ordinary believers secondhand. It was mediated to God’s people through their contact with the prophets or the priests or the kings, who were all, at the end of the day, living pictures of the Lord Jesus Christ. It was necessary under the old covenant for someone to say to you, “Know the Lord, let me share His revelation with you.” But now in Jesus Christ, the one final and true prophet, priest, and king—when we come to know Him, we’ve come to know the Lord.

Or, as the Apostle John puts it, “We’ve all received the anointing, and we don’t need someone to teach us” (see 1 John 2:27). Well, John was teaching the people who read his letter. The Scriptures are full of teaching. There are teachers in the church. So, what the Apostles mean is that we no longer need the prophet, the priest, the king, because we all know the Lord Jesus, and we know Him directly by the Spirit and through the Word. So, we no longer need mediators because we have one Mediator between God and man, the man Christ Jesus.

And at the end of the day, you know, as Isaiah says, the Lord Jesus Himself is the covenant. I think that’s probably why the word covenant doesn’t feature all that much in the New Testament. So, while the revelation of the covenant of grace in the Old Testament was wonderful, in Jesus Christ, it’s surpassingly wonderful. It brings us the eternal life, which Jesus said involves knowing the Father through the Son by the ministry of the Spirit. So, let’s rejoice in that. Let’s revel in it this weekend, and let’s thank God together for the covenant of grace.