After buying the book this past spring, I finally finished reading N.T. Wright's 144 page book on Scripture--The Last Word.
Wright is a British citizen, Bishop of Durham, and a member of the Anglican Community. He's one of the world's most respected biblical scholars. You can find some of his work here.
There were two things I found most helpful. First, "authority of Scripture" is a shorthand phrase that speaks of God's authority exercised through Scripture by means of the Holy Spirit. In particular, God's authoritative work is what He is doing through the crucified and risen Lord to change lives and bring about His kingdom on earth. In other words, God is using Scripture to proclaim the message of His Son that will change the world--a mighty work overseen by the Holy Spirit. So then, our allegiance is not to a Book. Our allegiance is to God who reveals and proclaims Himself (in part) through a Book.
Second, Scripture is best understood as a 5-act play. Act 1 is creation. Act 2 is the fall. Act 3 is Israel. Act 4 is Jesus. Act 5 is the church. Each act builds upon the other. Some themes are carried through the whole play. Some appear only for a time (like animal sacrifices and the Law in Act 3). So then, Wright says, we shouldn't expect a return to the Garden of Eden (Act 1) because what God is working toward is His kingdom over all the earth (end of Act 5). We shouldn't deny that evil exists (Act 2) and neither should we think that evil will not be overcome (Act 4-5).
This analogy is particularly useful because it explains why believers in the New Testament age don't obey every jot and tittle of the Law as believers did in the Old Testament age (with the coming of Jesus, the act/era of history has changed). It also explains why the New Testament's moral codes should not be nullified (we're still living in the age of the church).
While Wright covers a lot of ground in so few pages, I wish he devoted time to the question of the Bible's inerrancy and infallability. For this, I heartily recommend Dr. Dan Wallace's "My Take on Inerrancy."
If you're motivated to better understand the role the Bible plays in your faith, N.T. Wright's The Last Word is an excellent choice.