When I was in high school and college I often said I felt I was living in a time similar to the Fall of the Roman Empire.
Malcom Muggeridge, British soldier and spy, later journalist and author, came to faith well into adulthood. Afterwards he authored The End Of Christendom, a lecture along with Q&A, in which he said:
Christendom began with the emperor Constantine. Christianity began with the incarnation…
This clarification is necessary in 21st century America. It is also the angst I was trying to verbalize several years ago as a student. America has been changing. I would argue that though the United States does not have a “state religion” in that there is no preferred denomination, the state religion of America up until the past 50 years was a “christendom” almost synonymous with “cultural christianity.” Christendom, is not in all actuality Christianity, it is similar in many ways but not in all. The wars in the middle ages accentuate this point in that God does not pick sides between warring Christian Kingdoms, Jesus said “My Kingdom is not of this world.” Christendom however has slowly been rejected by our culture over the past decades as is evidenced in our social mores; from rejecting prayer in school, or display of the Ten Commandments in courthouses to the current scrutiny of evangelicals, and the many other social changes we are witnessing. Many once nominal Christians no longer claim to be so as there is no longer a social advantage in doing so.
As we are now full swing into the new millennium we have to readjust our vision. Muggeridge clarifies for us:
Christendom, however, is something quite different from Christianity, being the administrative or power structure, based on the Christian religion and constructed by men. It bears the same relation to the everlasting truth of the Christian revelation as, say, laws do to justice, or morality to goodness, or carnality to love—if you like, as Augustine’s City of God to the earthly city where we temporarily live.
The founder of Christianity was, of course, Christ. The founder of Christendom I suppose could be named as the Emperor Constantine. I believe…that it is not Christ’s Christianity which is now floundering. You might even say that Christ himself abolished Christendom before it began by stating that his kingdom was not of this world—one of the most far reaching and important of all his statements. Christendom began with the Emperor Constantine. Christianity began with the Incarnation.
— Malcolm Muggeridge, from The End of Christendom, p. 13
The disciples went to make disciples, not necessarily to ensure that the state and the church were always symbiotic. Some would argue that any time the state sponsors the church then you have something compromised, other times the state has tried to suppress the church, as in the former USSR, and yet the church did abide with fiery devotion and integrity.