The Disciples of John the Baptist were on THE cutting edge of what God was doing on Earth, for about a year, tops. They not only believed that they were, and then not only were, but they KNEW that they were. They were involved in God's premier work with humanity, for that window of time.
John himself apprehended fairly quickly that he had to decrease, and Jesus had to increase. But, did John's disciples catch on as quickly? John struggled with this dilemma a bit later on, but did they even get it? Ever?
After several months of rotting in prison, John began questioning. But John's disciples had visited him. Did they simply relay John's doubt or had they been the ones feeding John's doubt? For certain, the baptizer himself absolutely had every reason to doubt. But, bereft of their leader, John's disciples had reasons all the more. A question: Whose idea was it to go offer Jesus that challenge? Most assume it was John, but John may have been talked into it. We don't know. What we do know, at least, is that John's disciples marched in and issued their challenge with vigor.
It takes guts to stand up to the Man of the Hour. John's guys walked up to Jesus at the peak of his Galilean campaign, with the crowds all around, and directly called into question his own central claims. Point: These were not timid men! They had hung in with John for a year or so, eating bugs, facing down Sanhedrin inquisitors, fasting, and staying loyal long after support had dried up. They were doubters as much as their leader - and in all probability, perhaps more so.
Whatever its origin, Jesus answered their question without answering it. Then they left. With that, Jesus declared them the old wineskin. They clearly did not want to stick around and see what God might be doing through someone else. They simply wanted to go back to John. Even imprisoned, their loyalties and memories were easily held onto, and difficult to let go of.
We do know of one person for sure who was able to move on from that glorious work of God - Andrew. But then, Andrew left early, jumping from nearly the crest of John's ministry right into the earliest segment of Jesus' new movement. He made his choice to leave while the fire was still hot, which may explain why he felt no responsibility for care taking over the embers. There's a whole other lesson here, I suspect, but for some other time.
(By the way: I seriously doubt Peter ever left home and fish-roasting hearth long enough to be John's disciple; it seems far more likely that Peter stayed home to subsidize Andrews religious commitment; however, if Peter was John's, then Peter left John when Andrew did, also. The same point would apply.)
The last thing we hear of John's guys is when they come by to tell Jesus. He's dead. After that point, the gospels are silent as to their doings. Did they ever let go? Did any of them come back long enough to see Jesus' true glory revealed? Wishful thinking won't cut it. Perhaps some did. Perhaps not.
What we do know is this. Twenty-two years after John's death, someone in Alexandria Egypt had spent time teaching someone - at least one Jew, Apollos - all about John the Baptist, and less than the whole story about Jesus. Thus, it would seem at least some of John's guys left Judea, probably not very long after his beheading. They would then have spent the following years giving faint ear to whatever news came from Palestine about the new Jesus people. That means they spent over twenty years in Egypt, tending the fire of their own memories from one year in Israel.
Amazing. Astounding. But... does it seem so uncommon?
People who get involved with a new work of God these days often ask, How do we avoid turning into an old wineskin, eventually? Well, maybe you can and maybe you can't. But if you think you can, then you probably can't. And you ought to know why, already. Really.
John's disciples didn't do anything to become part of the cutting edge of God's work in their time. They just happened to be in the right place when God moved there, and they were smart enough to join in with what God was there doing.
Two years later, it wan't because they had changed in some way, that John's disciples became 'the old wineskin'. It was because they had not. Their problem was never that they got distracted in some way from their 'first love'. It was that they did not.
They loved being part of God's movement. What they missed was that God's movement... moves.