For the denominations given pride of place in Christendom, this dead idea is at the core of their decline. As Christianity ceased to be a faith to be embraced and became a mark of belonging in the larger culture of which it was claimed to be a part, faith practices atrophied, and cultural markers replaced them as evidence of Christian faith.
For many centuries, faith practices and cultural markers remained joined at the hip, reaching their apogee in the Victorian era. Be a good citizen, grow wealthy, be good to your spouse and children lived happily side-by-side with prayer, Bible Study, and doing what Christ directs you to do. But as doubts were raised about the Christian part of Western culture, the markers began to diverge from faith practices.
The final rupture between respectability and Christian piety began in the 1920's, as did so many of the cultural trends that continue today. Living in cities divorced from generational family ties, younger generations developed new ways of being "respectable," with the Christian faith practices more and more as a model for the way NOT to be respectable.
Christian faith became an object of dirision, as Clarence Darrow sought to humiliate William Jennings Bryan on the stand during the Scopes Monkey Trial. Faith practices were "backward" in a time confident that human scientific knowledge would lead to a better world. Those who practiced their faith in ways recognizable by the generations of faithful before them retreated from the culture at large into a dark corner, while those who had followed the path of respectability came to fear and despise those faith practices as the ways of the poor and the ignorant.
Respectability as a faith practice, though, has one major drawback-- it is not transformational. Respectability is the mark of the majority, the mark of belonging, and as such is always a moving target. To chase respectability, one must look like everybody else. It is dangerous to stick out in a respectable crowd. If respectability is one's aim, then one must always be a follower, wherever respectability leads.
So, now that respectability decrees that sexual practice is a matter of indifference, and that, if one is not indifferent to practices that the Scriptures call sin, then one cannot be respectable, those who have no Scriptural knowledge to fall back on, who know nothing of the real practice of the faith they profess, simply follow the rules of their culture. Their children abandon the "faith" they were raised in, and their denominations die.
Practicing the historic Christian faith now in the upper reaches of this culture is embracing downward mobility; it is a great way to lose the respect of respectable people.
But praying to Christ Jesus will change your life. Reading the Bible, believing God's promises, heeding the Spirit's call will save your life. Worshipping Jesus Christ as Lord and Savior in daily life will open your eyes to your life's calling. Jesus Christ transforms every life He touches-- and no life, however rich in respect and the things of this world can compare with knowing Jesus.
Let goods and kindred go, Martin Luther wrote so long ago; this mortal life also. The body they may kill, God's truth abideth still-- His Kingdom is forever.