What happens when you water down wine?

In the transcript, Les explains that Isaiah 1:22 is in such simple language that even children can understand it. The Jews understood this as part of their everyday experience. He asks what water does to wine: if you have an expensive French wine and water it down, you get something that probably isn't even worth trying to swallow. The allusion is that somebody was corrupting them, which is exactly what Paul is talking about back in Galatians. Les connects this to Paul's spiritual commission, noting that Paul did not do this with his commission.