Here is a sample of an interesting article from a few years ago by John Piper:
"God gives good press to doctrine. But surveys of evangelicals usually do not—until recently. In God’s book, knowing his Son and believing true things about him is liberty. “You will know the truth, and the truth will set you free” (John 8:32). God’s self-revelation in the Bible is not a wax nose. Paul calls it “the standard of teaching to which you were committed” (Romans 6:17). It’s a standard, a yardstick, a pattern. You measure truth by it. Elsewhere he calls it “the whole counsel of God” (Acts 20:27), and the “pattern of the soundwords” and “the good deposit entrusted to you” (2 Timothy 1:13-14). It does not change. Our everlasting salvation is determined by whether we believe it: “Whoever abides in the teaching has both the Father and the Son” (2 John 1:9). Depart from the doctrine, and you depart from Christ. Or, better, keep watch over your doctrine and “you will save . . . yourself” (1 Timothy 4:16).
That’s high praise for good doctrine. You would think evangelicals would agree. But we are more likely to hear things like, “Christ unites; doctrine divides,” or, “Ask, ‘Whom do you trust?’, not ‘What do you believe?’” The minimization of biblical doctrine is common. But if we are not willing to get a high estimation of doctrine from God, perhaps we can get it from George Barna.He has been surveying American evangelicals to see if we practice what we preach. He is finding that we don’t preach doctrine from the Bible, and therefore don’t practice differently from the world."
To read the rest of the article go here.