A LITTLE LEAVEN

Leaven (commonly known as yeast) is what causes dough to rise.

The Bible uses the term to represent a subtle yet destructive influence. Just as the introduction of a small amount of leaven permeates the whole lump of dough, a seemingly innocuous bit of false doctrine can spread into full-blown apostasy.  

Paul admonished the early church ... You were running well; who hindered you from obeying the truth? This persuasion did not come from Him who calls you. A little leaven leavens the whole lump of dough. (Galatians 5:7-9) 

A Christian must carefully examine every religious teaching that comes his way. Even if a spiritual leader uses the Bible as his source of inspiration, he can misinterpret Scripture by adding his own distorted suppositions. It often goes unnoticed by those who filter 'truth' through the words of a trusted preacher. The error can grow into a foundational tenet that corrupts everything that's built upon it. 

Spurgeon - One man’s influence may mislead thousands; one piece of false doctrine may taint our whole creed. If you have a wrong ground of confidence, you are wrong altogether.

Wayward church denominations and depraved demonic cults started with 'a little leaven' ... There were also false prophets among the people, even as there will be false teachers among you, who will secretly bring in destructive heresies, even denying the Lord who bought them and bring on themselves swift destruction. (2 Peter 2:1)

Neglecting small errors inevitably results in big problems. All it takes to cause a massive forest fire is one little spark. Benjamin Franklin's quote seems applicable ... 

For the want of a nail, the shoe was lost,

For the want of a shoe, the horse was lost,

For the want of a horse, the rider was lost,

For the want of a rider, the battle was lost,

For the want of a battle, the kingdom was lost,

And all for the want of a horseshoe-nail.

           

Always be on guard against false doctrine. The Holy Spirit will reveal the 'leaven' when you personally study the Word of God and seek His wisdom.