It is amazing how a single page inserted by publishers has had a significant impact. It is the page between the so called Old Testament and the New Testament. In my Bible it is a single page entitled "The New Testament". However, we must remember that the Bible is one book and there are two covenants; The covenant of works before the Fall of Adam and the covenant of grace unfolded thereafter. Yes that covenant of grace varies in its administration and it is consummated finally by Christ and his shed blood, but it is the same covenant of grace.
When we think of the Scripture as being one book it begins to change our perspective upon many things. Paul wrote to Timothy in 2 Timothy 3:14-17:
"But as for you, continue in what you have learned and have firmly believed, knowing from whom you learned it and how from childhood you have been acquainted with the sacred writings, which are able to make you wise for salvation through faith in Christ Jesus. All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work".
The Scriptures that Timothy learned from were Deuteronomy, Isaiah, Micah and Malachi. In thinking of the prophet Malachi, it is amazing how Mark's Gospel just continues where Malachi leaves off.
Malachi 3:1 "Behold, I send my messenger [John the Baptist], and he will prepare the way before me. And the Lord whom you seek will suddenly come to his temple; and the messenger of the covenant [The Lord Jesus Christ] in whom you delight, behold, he is coming, says the LORD of hosts".
Mark 1:1-4 "The beginning of the gospel of Jesus Christ, the Son of God.
As it is written in Isaiah the prophet, “Behold, I send my messenger before your face, who will prepare your way, the voice of one crying in the wilderness: ‘Prepare the way of the Lord, make his paths straight,’ ” John appeared, baptizing in the wilderness and proclaiming a baptism of repentance for the forgiveness of sins".
I would encourage all of us to reconsider and meditate upon the reality that the Bible is one book. This should enhance our appreciation of all the Books of the Bible and then to seek to understand all of them and to ask how each fits into the Lord's plan of redemption so that the church can grow in her knowledge of all Scripture.