At yeast it’s good.
Your boasting is not good. Do you not know that a little leaven leavens the whole lump? … 1 Corinthians 5:6
For kicks and giggles, I googled the phrase, “What’s the deal with the Israelites and yeast?”
The standard answer to the aversion towards yeast in Israelic practice is their hurry out of Egypt and it’s symbolism to sin - this is one of the verses that practices that.
However, I don’t think yeast itself is a symbol of sin, so hold on to your sourdoughs. Instead, the changing properties of yeast is used to illustrate to the Corinthians on the ‘puffing’ up quality of pride - their pride in thinking that they were better than everyone, and the acceptance of the crude sin mentioned before in the passage was allowed to stay thanks to their ‘enlightenment’.
Pride doesn’t stop at the area it’s allowed to rest in, but infects the entire lump, or in this case, the Corinthian church.
