The passage our writer is wondering about is found in Mark 2.21-22 and reads: "No one sews a piece of unshrunk cloth on an old cloak; otherwise, the patch pulls away from it, the new from the old, and a worse tear is made. And no one puts new wine into old wineskins; otherwise, the wine will burst the skins, and the wine is lost, and so are the skins; but one puts new wine into fresh wineskins."
When Mark wrote his gospel he often used a powerful rhetorical device called "sandwiching." Sandwiching is when the writer begins telling a story, then in the middle switches to another story, and then finally finishes the first story. In other words, there's a story tucked into the middle of another. Now, when Mark does this, the middle piece is always a commentary on the original story, and that's what we have with this parable.
To see this, we have to begin with verse 18 where we read: "Now John's disciples and the Pharisees were fasting; and people came and said to him, 'Why do John's disciples and the disciples of the Pharisees fast, but your disciples do not fast?' Jesus said to them, 'The wedding guests cannot fast while the bridegroom is with them, can they? As long as they have the bridegroom with them, they cannot fast. The days will come when the bridegroom is taken away from them, and then they will fast on that day" (Mark 2.18-20). This story begins an account of the Pharisees complaining about Jesus. But then suddenly, we read the parable of the unshrunk cloth and wineskins and finally Mark continues the story of the Pharisees complaining, this time about working on the Sabbath day (verses 23-27).
So, what does the parable mean? Well, to begin with we have to understand new patches and old wineskins. First, it is common knowledge among the garment industry that if you sew a new piece of denim that hasn't been preshrunk onto an old, worn pair of jeans, the first time you wash them the new patch will shrink and the jeans will be a mess. Likewise, in ancient days, before wine bottles were invented, wine was stored in wineskins made of animal hide or gut. If unfermented wine (new wine) was put into a wineskin that had been previously used, the fermentation process would burst the wineskin. So, when we compare the parable to the stories about the Pharisees that precede and follow it we can see that what Jesus means is that new ideas aren't compatible with old practices. In our modern vernacular (okay, maybe not so modern) we might say, "You can't teach old dogs new tricks."
How this applied to the Pharisees, and indeed how it applies to us today, is that Jesus is saying that organized religious structures are reticent to change with the times and that it may be pointless to try and change them.
A case in point. Most churches honor the long-time traditions of worship. This includes sitting on benches (pews), singing music written literally centuries ago, and even using language that is archaic (words like doxology, gloria patri, benediction, invocation and so on-all words unfamiliar to most people outside the church). However, when some pastor or group of people try to update worship so that it can be understood or appreciated by younger folks, or by those outside the church, most of the time an inner war breaks out within the congregation. In other words, like Jesus said, trying to put a new patch onto old jeans only makes the tear bigger.
Recently, I've seen two commercials that speak to this. A chocolate company famous for its unchanged signature chocolate bar has an ad that says, "Change in bad." On the other hand, I've seen an lube/oil/filter company with an ad that says, "Change is good." The reality is change is neither bad nor good. Change is inevitable.
But sometimes it's easier to start over than it is to effect a change. Which is why newly started churches often attract many, many people to their worship-because they haven't had to deal with change and the struggles that come from it. Instead, they chose to begin with a modern method of communicating the gospel.
Jesus, Luther, and John Wesley did not intend to start new religions/denominations. They all meant to bring about changes to existing structures. But none of them accomplished their intentions. Instead we enjoy the fruits of Christianity, Protestantism, and Methodism. One has to wonder, will the church learn the lesson of the patch and wineskins, or will we see the dawn of something new-again.