Our Scripture reading today is Galatians 5:9, "A little leaven leaveneth the whole lump."
For the most part, leaven in the Bible always stood for something that was evil. A warning is given by the Apostle Paul to the Galatian believers about allowing just a little bit of their legalistic way of thinking would impact everything in their life. They had been delivered from the law as a means of salvation but were quickly going back to the law.
Anything that takes away from the exclusivity of Jesus Christ being the only way to Heaven should be avoided. He is still the only way to the Father. The lost are still saved by grace faith and the saved still live by grace through faith. We must not allow anyone to pull us away from the sound doctrine that we have been given.