“And no one puts new wine into old wineskins; or else the new wine will burst the wineskins and be spilled, and the wineskins will be ruined.” (Luke 5: 37)
Here Jesus uses a metaphor that had probably been the experience of some of those who heard this teaching. Undoubtedly they had made the mistake of putting new wine, or unfermented wine, in an old brittle wineskin. They would hang that wineskin on the wall of their home to let the wine ferment. But one afternoon while they were taking a siesta there would be a loud popping sound and they would see wine running down the wall. They would immediately know they made the mistake Jesus was describing. The expanding fermenting wine burst the wineskin.
By this metaphor Jesus was teaching that His truth was like unfermented wine. When they took that truth into their mind, if they did not yield to the pressure of that truth and apply the teaching it would literally blow their mind!
We place such a high value today upon knowledge that many people think knowledge is virtue. However, it is the application of knowledge that leads to virtue and wisdom. Jesus taught in another place that it is when we do what He teaches that we will know His teaching is the Word of God (John and 7:17).
This is also a warning from Jesus. If we build up a reservoir of the truth Jesus taught that we never apply, that unapplied teaching can give us so much conflict it can make us sick. The greatest truth this world has ever heard came through Jesus. Resolve to do it before you know it. The application of the truth Jesus taught can convert you into a new wineskin.