So many Christians today identify themselves with some ‘single issue’ (a concept drawn from politics) other than the cross, other than the gospel. It is not that they deny the gospel. If pressed, they will emphatically endorse it. But their point of self-identification, the focus of their minds and hearts, what occupies their interest and energy, is something else: a style of worship, the abortion issue, home schooling, the gift of prophecy, pop sociology, a certain brand of counseling, or whatever. Of course, all of these issues have their own importance. Doubtless we need some Christians working on them full time. But even those who are so engaged must do so as an extension of the gospel, as an extension of the message of the cross. They must take special pains to avoid giving any impression that being really spiritual or really insightful or really wise turns on an appropriate response to their issue.
—D. A. Carson