We affirm that all the Bible - Old Testament and New Testament - is the word of God. It is truly amazing the many ways God used to communicate His word -- 40 different men over a period of fifteen hundred years! Beyond even that, consider the ways He communicated His will - visitations of angels, dreams, visions, prophets, even the casting of Urim and Thummim.

But consider Hebrews 1:1-2:

Long ago, at many times and in many ways, God spoke to our fathers by the prophets, but in these last days he has spoken to us by his Son, whom he appointed the heir of all things, through whom also he created the world.

There is significance in the but. In that one, small word is about 400 years of silence. That was "long ago." But now (to the writer of Hebrews) is the last days. These last days refers to the last days of the Jewish economy. The last days of the Old Covenant. In these last days, God has spoken by the Lord Jesus Christ. This is the last revelation God would ever make. And what a better revelation! The Old was revealed at many times - over many centuries. The New is revealed in this one time - within the life of the Messiah. The Old was revealed in many ways. The New is revealed in this one way - spoken to us by his Son. The Old was spoken to their fathers. The New is spoken to us. The Old was spoken through prophets. The New is spoken through the Prophet. A prophet was a man who spoke for God. Christ as the God-Man speaks and is God.

Consider the message: Romans 16:25-27

Now to him who is able to strengthen you according to my gospel and the preaching of Jesus Christ, according to the revelation of the mystery that was kept secret for long ages but has now been disclosed and through the prophetic writings has been made known to all nations, according to the command of the eternal God, to bring about the obedience of faith— to the only wise God be glory forevermore through Jesus Christ! Amen.

The mystery is the whole Gospel -- all of its parts -- the Trinity, the Son of God, the incarnation, the resurrection, the ascension, etc. (God's mystery, which is Christ, Colossians 2:3). There were hints all along, shadows and types, but now, in the last days, the fullness of this mystery has been revealed by Christ and his apostles. And here is another better aspect of this revelation: the Old was only to the Jews. But the New is to all nations of the world. The eternal God commanded this Gospel be given just this way, at just this time, and to these people. Why? To bring about the obedience of faith. The Gospel comes to bring faith, to bring repentance, to bring holiness, to cause men to walk with their Creator.

So, why was this mystery not revealed for centuries? According to Romans 15:4, "whatever was written in former days was written for our instruction, that through endurance and through the encouragement of the Scriptures we might have hope." The Old was for instruction. The Old teaches about the Trinity, the Son of God, the incarnation, etc., though darkly. It did not teach to complete the lesson, but to introduce the lesson. It gave the description for the APB, so the One sought could be recognized. It taught what to believe and how to behave. The encouragement of the Scriptures offered hope, hope for eternal life. "And this is eternal life, that they know you the only true God, and Jesus Christ whom you have sent." (John 17:3)

When was the transition? Luke 16:16 says,

The Law and the Prophets were until John; since then the good news of the kingdom of God is preached, and everyone forces his way into it.

So, the transition was at John the Baptist. Before John the Baptist, the Law and the Prophets - the Old Testament - the Old Covenant message. Beginning with John the Baptist - the New Testament - the New Covenant message - the good news of the kingdom of God.

Ephesians 2:19-21:

So then you are no longer strangers and aliens, but you are fellow citizens with the saints and members of the household of God, built on the foundation of the apostles and prophets, Christ Jesus himself being the cornerstone, in whom the whole structure, being joined together, grows into a holy temple in the Lord.

The foundation is the apostles and prophets. This is not the Old Testament prophets and New Testament apostles. The word order is not an accident. These are New Testament apostles and New Testament prophets. Note 3:4, 5, "When you read this, you can perceive my insight into the mystery of Christ, which was not made known to the sons of men in other generations as it has now been revealed to his holy apostles and prophets by the Spirit." The church is built on these New Testament apostles and prophets.

Christ Jesus himself being the cornerstone. As it said in Psalm 118:22, "The stone that the builders rejected has become the cornerstone." This signifies his excellence, very similarly to the way we refer to someone as a "pillar of the community." Christ is the foundation and the supports.

1 Peter 1:10-12:

Concerning this salvation, the prophets who prophesied about the grace that was to be yours searched and inquired carefully, inquiring what person or time the Spirit of Christ in them was indicating when he predicted the sufferings of Christ and the subsequent glories. It was revealed to them that they were serving not themselves but you, in the things that have now been announced to you through those who preached the good news to you by the Holy Spirit sent from heaven, things into which angels long to look.

The prophets searched and inquired carefully into the coming of Christ. They looked and longed for His salvation. We see these things clearly now. Our view is not blocked by shadows and sacrifices, but cleared by the One Sacrifice. They were serving not themselves but you. They did serve. But they served us who have come much later. They are for our instruction. We can compare prophecy with fulfillment. You do not cover your eyes to find your way in the light, but you do use a flashlight to find your way in the dark. So we use the New Testament to make the Old Testament clear.