Worldliness: The First Sign of Backslide BY Dr Joel Beeke

Quoting Joel Beeke . . .
"When the church begins to backslide, the first, outward and visible sign is usually an increase in worldliness. In the way of life, in talk, and even in dress and fashion, the spirit of the world begins to be found more and more in church circles. That which crept into the church ashamedly in former times, so to speak, begins to walk in freely, often covered and overlooked instead of exposed and admonished. The black and white line of separation between godliness and worldliness, between the world and the church, between those who fear God and those who fear Him not, becomes increasingly more gray.
Instead of walking opposite directions, the world and church begin to have more in common with each other to the church's great detriment. Some of its members begin going to worldly places, partaking of worldly forms of entertainment, and become friends of worldly people. Some thoughtlessly take television, the modern-day sin-box and devil's classroom, into their own homes, quickly addicting themselves to its worldly mentality.
Worldly people, worldly entertainment, worldly fashions, worldly customs, worldly places - is this not what Hosea warned against when the Spirit directed him to write: "Ephraim hath mixed himself among the people"? [Hos 7:8] Is not the sin of increasing worldliness the church's first downward and tragic step in an ever-increasing spiral of backsliding? ''

From:
God's Church Bent to Backsliding - (Encyclopedia Puritanica)