In his awesome book, Selling Jesus, by Douglas D. Webster, the author gives an incredible quote about the lack of spiritual discernment in American church growth and marketing today:
"American Christianity is increasingly tolerant of any and all methods, as long as they bring NUMERICAL results. We don’t hear people praising the Lord because millions of people watch the NFL Super Bowl, but if 5000 people attend church, it must be God’s doing! We have virtually eliminated discernment of the will of God -- and sadly, that’s the equivalent of losing the keys of the Kingdom.
Anything goes as long as it is defended for the sake of evangelism or promotes church growth. The single most decisive support for new methods is POPULARITY. If people are buying, the product must be good. Public opinion has become an arbiter of truth, dictating the terms of acceptability according to the marketplace. The sovereignty of the audience makes serious, prayerful thinking about the will of God unnecessary, because opinions are formed on the basis of taste and preferences rather than careful biblical conviction and thoughtful theological reflection. Americans easily become "slaves of slogans" when discernment is reduced to RATINGS."