Andy Nasselli has a great excerpt from Douglas J. Moos’ work on Romans: Encountering the Book of Romans; A Theological Survey. Moo is discussing “The Many Uses of Quotations” (p. 161)
Let me just give a teaser:
We have encountered several places in Romans where Paul does not seem to apply the Old Testament in quite the way the original Old Testament context would seem to validate. This creates a theological problem. How can a New Testament writer use the Old Testament to claim that something is true when the Old Testament does not even teach what he claims it does? Such a procedure would be like our trying to prove a doctrine from a text that we have misunderstood. Understandably, we would convince few people. Answers to this problem, which theologians have discussed for years, are not simple. In fact, each of the texts has to be taken on its own, because they present different kinds of problems. But one part of the solution is to recognize that New Testament writers sometimes use the Old Testament not to prove a point but to borrow its language and ethos. An illustration will make the point.
Moo gives a great example that sheds a totally new light for me on many of those passages. I highly suggest you check it out. Whether you agree or not, it deserves your attention. Find it here.