The author tries to guide us as modern readers of Scripture to read and understand the Bible, which was written to others in such a manner that it speaks to us.
How is the Bible a unity? The Scriptures makes it clear that God has a unified plan for all of history. God’s ultimate purpose realized in the fullness of time is to unite all things in Christ (Ephesians 1:10). The Old Testament contains God’s promises and covenants. All of these were shadows, prefigurements, and types.