“The Old Testament is the New concealed and the New Testament is the Old revealed.”
The New Testament contains a large number of Old Testament quotations. There are, at least 295 separate references to the Old Testament. These occupy some 352 verses, or more than 4.4 per cent. Therefore one verse in 22.5 of the New Testament is a quotation from the old. Jesus frequently quotes from the Hebrew scriptures, now commonly called the Old Testament. He most notably quotes the Psalms, in life lesson context. But He also applies some scriptures prophetically.
Christians generally recognize the Holy Bible (both Old and New Testaments) as God’s Word. There are many Old Testament promises still to be fulfilled. One prophecy is through Abraham and his children, “all the families of the Earth will be blessed”. (Genesis 12:1-3, 18:18, 22:18.) All includes the living and the dead. The dead have not been resurrected and blessed.
The blesser class of Abraham’s children are Jesus and His church. The New Testament book of Galatians provides an excellent summary. Galatians 3: 7-8 “…those who are of faith who are sons of Abraham. The Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel beforehand to Abraham, saying, “All the nations will be blessed in you.” Vs 27-30 “For all of you who were baptized into Christ have clothed yourselves with Christ… And if you belong to Christ, then you are Abraham’s descendants, heirs according to promise.”
By this, the New Covenant could be implemented. Hebrews 8:6, “But now He (Jesus) has obtained a more excellent ministry, by as much as He is also the mediator of a better covenant, which has been enacted on better promises.” 2 Corinthians 3: 4-6,17, “Such confidence we have through Christ toward God. Not that we are adequate in ourselves to consider anything as coming from ourselves, but our adequacy is from God, who made us servants of a new covenant, not of the letter but of the Spirit…We all, with unveiled face, beholding as in a mirror the glory of the Lord, are being transformed from glory to glory,..”
Soon the New Covenant of Jeremiah 31 will be ratified. Jeremiah31:31, 33-34 (ESV), “…I will make a new covenant with the house of Israel and the house of Judah (extending to all mankind)…I will put my law within them, and I will write it on their hearts. And I will be their God, and they shall be my people. And no longer shall each one teach his neighbor and each his brother, saying, 'Know the LORD,' for they shall all know me, from the least of them to the greatest, declares the LORD. For I will forgive their iniquity, and I will remember their sin no more."