All that glitters is not gold goes the old saying. In a similar vein, Os Guinness and David Wells have alerted evangelicals about weakness they observe in the apparent success of today's evangelicalism.
"(T)he strong timber of the tree of evangelicalism has historically been the great doctrines of the Bible—God’s glorious perfections, man’s fallen nature, the wonders of redemptive history, the magniﬁcent work of redemption in Christ, the saving and sanctifying work of grace in the soul, the great mission of the church in conﬂict with the world and the ﬂesh and the devil, and the greatness of our hope of everlasting joy at God’s right hand. These things once deﬁned us and were the strong ﬁber and timber beneath the fragile leaves and fruit of our religious experiences. But this is the case less and less."
There's more at this link.