John Piper from 1989:
Let me just mention one feature to watch out for in the recognition of wolves. As I have watched the movement from biblical faithfulness to liberalism in persons and institutions that I have known over the years, this feature stands out: An emotional disenchantment with faithfulness to what is old and fixed, and an emotional preoccupation with what is new or fashionable or relevant in the eyes of the world.
Let’s try to say it another way: when this feature is prevalent, you don’t get the impression that a person really longs to bring his mind and heart into conformity to fixed biblical truth. Instead you see the desire to picture biblical truth as unfixed, fluid, indefinable, distant, inaccessible, and so open to the trends of the day.
So what marks a possible wolf-in-the-making is not simply that he rejects or accepts any particular biblical truth, but that he isn’t deeply oriented on the Bible. He is more oriented on experience. He isn’t captured by the great old faith once for all delivered to the saints. Instead he’s enamored by what is new and innovative.
A good elder can be creative. But the indispensable mark when it comes to doctrinal fitness is faithfulness to what is fixed in Scripture—disciplined, humble submission to the particular affirmations of the Bible—carefully and reverently studied and explained and cherished. When that spirit begins to go, there’s a wolf-in-the-making.
Excerpted from Watch Out for the Wolves Within.