The two-readings view (hereafter TRV) says that we should first read the Old Testament as though the New Testament did not exist, and as though Christ had not come. The reasoning typically runs along the lines of seeking to ensure that we understand the text in its original literary and historical context. How would this have sounded to the original audience? What impact would it have had? Now, there are certainly important points here which we cannot afford to ignore. We need to know context, literary and historical. The Old Testament writings were written at a particular time and place, and there is a good reason for why those writings were written just then. It is good to seek answers to those questions. At this point, I might add a gentle reminder to TRV folks that opposing views do not necessarily ignore the context. That is not primarily where our disagreements lie (although how much weight we give to ANE materials in determining the nature of Scripture is certainly an issue of disagreement. On this I will only say that there is a difference between using ANE materials to understand how a text would have sounded to an original reader versus using the ANE materials to determine what Scripture actually is). It is not primarily the context of the OT that is under dispute (with the caveat just mentioned) but rather the intention of the OT that is under dispute. As Rich Barcellos helpfully put it to me, does the Christological reading of the OT predate the NT or not?
The second reading of the TRV is what we do after we re-factor Jesus and the New Testament into the equation, usually as a surprise ending. The apostolic hermeneutic is often likened (in the TRV) to rabbinical methods of interpretation (key-word exegesis, etc.). Oftentimes, the meaning that the NT writers see in the OT has little or nothing to do with what the OT itself actually says in its original context. There is often (not always!) a radical break between the meaning of the OT in its own context and the meaning that the NT authors assign to the OT text.
The problem with the TRV comes in the area of what the Old Testament actually intends. On a TRV, it is possible for a New Testament author to twist the meaning of the OT into something it was never originally intended to say. Matthew’s use of Hosea 11:1 is an excellent example. We may ask the question this way: is Matthew’s use of Hosea a legitimate way of understanding what Hosea intended to say? Or, better yet, what God intended to say through Hosea? The standard Vossian way of interpreting Matthew’s use of Hosea is simply to note that Matthew everywhere describes Jesus as reliving Israel’s story, but in a righteous way (thus contrasting with Israel). Matthew treats Israel as not only typologically pointing to Jesus, but also as being embodied (in a faithful way) in Jesus. So, when Matthew looks at Hosea 11:1 (“Out of Egypt I called my son,” in the original context plainly speaking about God calling Israel out of Egypt in the Exodus), he sees Hosea not only talking about the old Exodus, but also talking about the new Exodus that Jesus brought into being by embodying faithful Israel. It is what he understands Hosea to be saying. The TRV would say that Matthew’s interpretation has nothing to do with what Hosea meant (and notice here how divine authorship fades very quickly from view here).
The deeper problem with the TRV lies in the character of God. If God has written the Bible, then God has changed His message from the OT times to the NT times. That means that God changes His mind and is open to the future. The TRV cannot avoid an ultimately open theistic view of God’s character. They would probably respond that it’s okay that God does this because the changeability resides in the humanness of Scripture. This is just God using the messiness of humanity to communicate to humans. This is a smokescreen, unfortunately. God inspired humans to write the Bible in such a way that there are no errors in recording God’s words. Yes, humans are fallen and sinful. That does not mean that they distorted God’s message in any way. They were carried along by the Holy Spirit. For the TRV to be correct, the message had to have been garbled in transmission. Yes, we see humanness in the Bible. Paul does not sound like John. We can tell the difference. God used the personalities of each writer. But He did so in such a way that there are no garbled transmissions. In short, the TRV is ultimately incompatible with our doctrine of inspiration, and it is incompatible with our doctrine of God.