"Your pride in your church is lamentably out of place. Don’t you know how a little yeast can permeate the whole lump? Clear out every bit of the old yeast that you may be new unleavened bread! We Christians have had a Passover lamb sacrificed for us—none other than Christ himself! So let us 'keep the feast' with no trace of the yeast of the old life, nor the yeast of vice and wickedness, but with the unleavened bread of unadulterated truth!" 1 Corinthians 5:6-8
So, literally and figuratively, Jesus brings to the table, to the "feast," Himself: the perfect Passover Lamb. And what does Paul say that we're invited to bring? The unleavened bread. That combination of salt, water and flour.
The "salt" that is the Good News, the Gospel, the Reality of who Jesus was and is, and all that's He's done and is doing.
The "water" that is His Holy Spirit, the Spring of Life that wells up within us, the inward experience of His very life.
And the "flour," our personal personalities, refined and made ready for His purposes: consecrated for new, beautiful things.
Friends, there is NO NEED for the "yeast of the old life," here: we are a New Ingredient of a New Life in a New Covenant.
All things have been made New on this Monday!