The whole thing isn’t long, but here are a couple of paragraphs
This is why there can be so many evangelical pastors and churches without any positive effect on Christinaity and Evangelicalism as a whole in America – we assume our beliefs rather than practice them. It is quite easy to claim evangelical beliefs – post them in the bulletin, use key words like inerrancy and justification in sermons, brow beat liberals for their opposing views – but it is quite a difficult task to actually put into practice the doctrines we hold so fervently. It is hard to find a church that centers its ministry on God’s Word rather than the culture.
My hunch, based on the fruit of our labors, is that most our growing evangelical population knows little of what it means participate in or run a ministry on the idea that God’s Word is inerrant. As Schreiner points out, this comes back to our fundamental distrust in the fact that God’s Word is actually sufficient. Simply put, our evangelical churches just don’t truly believe that God’s Word alone is capable of producing God-glorifying Chrisians (if they even get to the point where they think that is the goal).
The Schreiner article he quotes is here: http://www.beginningwithmoses.org/articles/preachingbt.pdf
(For the record, I don’t agree with everything Schreiner says in this article – espcially touching the role of the law for the New Testament believer. But his observations about the state of much modern evangelicalism in practice are shrewd in the introduction, as are his generally carefully-qualified comments on how biblical theology should shape our preaching.)