Q & R: as valid as the Bible?

Here’s the Q:

I’ve read many of your books and have found them both inspiring and helpful. I have a question which I would be interested and grateful to have your response to:
Should Christians give books/blogs/letters etc written today about faith/doctrine/following Jesus etc equal authority as the Bible? – If we believe that God still talks to/inspires people today as much as he did to Paul and the other writers of the Old and New Testament shouldn’t it follow that what he says to preachers/teahers/authors etc today is just as valid, if not more so because they have been written by people in our time/context/culture etc? Or is this massively undermining (and missing the point of) the “authority” of scripture?
I hope that makes sense and isn’t too heretical a question!?

Here’s the R:
This is an important question. In general, I think the writings and words of many Christian leaders across Christian history have been given equal authority to the Bible – and more. But they haven’t been given that authority overtly: they have been given it covertly.
Their writings aren’t added to the Bible. 1 & 2 Augustine, 1 & 2 Aquinas, 1, 2, and 3 Calvin, or the Notes of Darby-Scofield-Hagee weren’t added after 3 John, Jude, and Revelation.
But their writings and thoughts have deeply influenced how millions of us have read the Bible. These “authority figures” set up alternative framing stories or sets of assumptions about what words mean and how biblical texts work … and in that sense, they’ve done something far more powerful than being added to the Bible: they have been used to set limits on the way Bible readers read every word that is already in the Bible.
So – your question is terribly important because it gets us thinking about the vexing question of authority – and how groups, texts, and traditions have authority. I hope that we can go back and give Jesus’ words a fresh read in this light – to see what he says about authority, and how he models it. I keep going back to a line of thinking from the brilliant South African missionary and missiologist David Bosch. “It is when we are weak that we are strong,” he said. So our encounters should be characterized, not by claims of authority (“Accept what we say because we said so!”), but by vulnerability:

The people who are to be won and saved should, as it were, always have the possibility of crucifying the witness of the gospel. (TM 485)

I wonder if we have fully grasped the radical redefinition of authority embodied in Jesus. It’s not simply the power to command obedience. It’s the power to lay down one’s life for one’s friends … the power shown in weakness … the power shown in kindness and forgiveness and suffering … the persuasiveness that speaks softly and doesn’t strike back when ignored or misinterpreted. Maybe (following Michael Gorman) we should call it “cruciform authority.”
If that’s the case, then our explorations of biblical authority should begin with a re-opening of the question of how we define authority in the first place, how we expect it to work in the world, how we hope to respond to it and exercise it … in light of Christ.