There are verses that appear to point to a unity between the old and new testaments. According to the Christian Biblical Church Of God, which suggests the following examples, when you study the scriptures they show you that God intended for the whole bible to be his voice.
Here God provides us with the standard by which to seek him and tells us how to find those that speak the truth. "To the law and to the testimony! If they do not speak according to this word, it is because there is no light in them." (Isa. 8:20). A second example comes from this chapter. It is a prophesy which says that the new testament will be written by Jesus' disciples. It says: "Bind up the testimony, seal the law among my disciples".
Following on from the last example, in this book the apostle Paul writes to the Colossians and reveals that he would help "complete the word of God".
Here is Paul again in a letter to Timothy. "But as for you, continue in the things that you did learn and were assured of, knowing from whom you have learned them; and that from a child you have known the holy writings [the Old Testament], which are able to make you wise unto salvation through faith, which is in Christ Jesus". Paul again shows that both the old and new testament is inspired by God with this verse: "All scripture is God-breathed and is profitable for doctrine, for conviction, for correction, for instruction in righteousness; so that the man of God may be complete, fully equipped for every good work".
