The Jewish nation of Israel lived under the Mosaic covenant. This covenant was supposed to be temporary. It was there to reveal their sinfulness, to teach them the gospel in pictures, and to lead them to God's Messiah, High Priest, Prophet, and Lamb. While the people promised confidently that they could keep God's covenant, they failed, and failed, and failed all the way into exile and beyond. God knew that would happen and in Deut 30:1-10 God promised that one day He was going to make them all able to keep His law and covenant so they would experience His blessings. Now at this point this promise is not called a covenant, but when we examine other passages that more clearly refer to the new covenant, than we can see that this promise in Deuteronomy 30 is indeed referring to the new covenant. When we look at the whole of the Old Testament, we see many passages that promise a new covenant. Almost all the prophets reveal aspects of this new and glorious covenant. For example look at Ezekiel 11:14-21, Ezekiel 36 22-36, Ezekiel 37: 15-28, Hosea 2:14-23, Hosea 14. But the clearest passage that explains the new covenant is found in Jeremiah 31:31-40. Part of this passage is quoted in Hebrew 8:8-12. We will look carefully at this new covenant for it reveals to us why we baptize only believers.
It is clear from scripture that we who are Christians live in the new covenant. At the first Lord's Supper, Jesus, when He was about to pass the cup of wine, stated that, " This cup that is poured out for you is the new covenant in my blood." Luke 22:20 In Hebrews 9: 15-22, we learn that a will or covenant cannot come into effect without the death of the one who made the will. The death of Christ opened up to us God's will or covenant. The death of Christ instituted the new covenant. Again Hebrews 8 makes it clear that we enjoy the benefits of living in this new covenant.
It is important to remember that this new covenant was originally promised to Israel. The new covenant was to be the fulfillment of all the other covenants. What the Abrahamic, Mosaic, and Davidic covenants promised, the new covenant delivers. When you look closely at all the passages about the new covenant you will see a consistent pattern in what is promised. The new covenant promises a great return of Jews to their own land. There in the land they will be ruled by the Son of David. It will be a time of great peace, blessing, and prosperity. But before this can happen there will be a great conversion of Jews. It will be a national repentance; a nation as a whole being born again, something the law could not give. See Ezekiel 37. The Holy Spirit is also promised in the new covenant for it is He who will work this great internal change. So we see material or physical blessings promised in the new covenant but also spiritual blessings. But since Israel has rejected her Messiah, she lives outside the blessings of the new covenant. Now Gentiles and believing Jews can participate in the spiritual blessings of new covenant though faith in Jesus Christ, the Seed of Abraham. (Romans 11) So while the new covenant is instituted or begun, there remains a complete fulfillment. This will happen when the nation of Israel is born again and gathered into their promised land under the rule of Jesus the Son of David. This full fulfillment we, Gentiles, will experience as well during the blessed reign of Christ.
Now let us look at Hebrews 8:8-12 to see in detail what God promises to give to those now in the new covenant.
1) This covenant is unbreakable.
We can see this in verses 8 and 9. There is a comparison between the new covenant and the old mosaic covenant. The people of Israel did not continue in the covenant God made with them at Sinai. They could not keep its demands. They were unable to do all that God commanded them. But this was to change in the new covenant for God was going to change the people internally. Notice all the "I wills", God promises to provide in Christ all that was needed for his people to keep this covenant. There are no covenant obligation for those in this covenant. Christ has done it all.
2) God promises to give His people a new heart. verse 10a
The Mosaic covenant had laws written on stone tablets. But now the law would be written on the hearts of His people. Having the law written on a person's heart or mind means that God's law would become the driving force of our beliefs, affections, words, and deeds. We will delight to do God's law. We approve of God's law. We look at God's law as God sees it. This is what happens at regeneration. This is what is promised in Ezekiel 36:26 " I will give you a new heart and put a new spirit within you; and I will remove your heart of stone and give you a heart of flesh."
3) God promises reconciliation and restoration. verse 10b
God promises that He will be their God and they shall be my people. This promise is found through- out the Bible. In Leviticus 26:12 God promised this if His people would keep His law. In Hosea 1:9, God says that He is not Israel's God and they are not His people because of their sins. But yet in the next verse promises a time when this relationship will be restored. In 2 Cor 6:16, this promise is also applied to individual believers, who were separated from God by their sins but now are reconciled to Him though Christ. In Rev 21:3 and 7, God promises that in the new heavens and earth there will be unhindered fellowship with Him.
4) Everyone in the new covenant will know the Lord. verse 11
To know the Lord is not to simply know about God, but to have a close personal relationship with God. The sons of Eli did not know the Lord. 1 Sam 2:12 Samuel who worked in the temple did not know the Lord before God appeared to him. 1 Sam 3:7 A theme in the book of Hosea is that Israel did not know the Lord, in spite of their apparent religious devotion. We can see something of the meaning of this expression when it used to describe sexual intimacy. Adam knew his wife Eve. Gen 4:1 In Matt 7:23, Jesus says to those who did many mighty works in His name, that He never knew them. These were self deceived unbelievers who knew about Christ but did not know Him. Jesus knows about them, but He doesn't know them. In the old covenant there were people who did know God. But most of the time most Jews did not know God. Many had no personal saving relationship with God. But in the new covenant it is promised that all people will know God. To put it another way, In old covenant Israel there were covenant members who needed to be evangelized. In the new covenant all members are saved; we don't need to evangelize covenant members.
5) God promises complete and irrevocable forgiveness. verse 12
Forgiveness was given in the Old Testament based on the promise of a coming Savior who would suffer the punishment that we deserved for our sins. In the new covenant God gives forgiveness based on the finished work of Christ on the cross. This once for all sacrifice washes away our sins forever.
6) God promises the indwelling of the Spirit
It is important to note that in Ezekiel 36:27, which is also a promise of a new covenant, God promises to put His Spirit in them. "And I will put my Spirit within you, and cause you to walk in my statues and be careful to obey my rules." So we see at Pentecost that the Spirit of God comes upon His people. see Joel 2: 28-32 Every time a person is born again the Holy Spirit indwells them and gives them spiritual gifts. This outpouring of the Spirit will also happen to Israel in her future national conversion.
Infant baptism fails on every characteristic of this new covenant. Every point listed above prevents the idea that children of believers or any unconverted person can be part of this new covenant. Only those who are born again, indwelt by the Holy Spirit, forgiven, and reconciled to know the Lord are members of this new covenant. Baptism is a sign of this glorious covenant. So baptism is to be administered only to those who show the evidences of the new birth.
This post became longer than I planned and it really is only a brief explanation of the new covenant. So, I will explain what baptism means in the next post in this series.