Get the picture! I can imagine the Apostle Paul ministering to a city and a great revival occurring as a result. And then, as he was leaving that city, the spiritual goods departing that city leaving it in a state of carnality.
The Apostle Peter saw this too...
13 Nevertheless we, according to his promise, look for new heavens and a new earth, wherein dwelleth righteousness.
14 Wherefore, beloved, seeing that ye look for such things, be diligent that ye may be found of him in peace, without spot, and blameless.
15 And account that the longsuffering of our Lord is salvation; even as our beloved brother Paul also according to the wisdom given unto him hath written unto you;
16 As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction. - 2 Peter 3
They went from spiritual to natural! In which Paul also grieves...
Beside those things that are without, that which cometh upon me daily, the care of all the churches. - 2 Corinthians 11:28