In the Parable of the Leaven, as presented in Matthew 13:33 and Luke 13:20-21, Jesus Christ forewarns of internal doctrinal distortions that would affect God's church through the centuries until His second coming. Leaven, in this context, symbolizes corruption and evil, reflecting a process of disintegration and decay. Physically, leaven is a substance like yeast or fermented dough that causes bread to rise, but its symbolic use here aligns with negative connotations of corruption. Jesus Christ employs this symbol to indicate the evil doctrines of groups like the Pharisees, Sadducees, and Herod, characterized by hypocrisy, skepticism, and worldly indulgence. Over time, the leaven of distorted doctrine has manifested as greed, pride, control, and worldly desires, subtly striking against the truth within the church. The parable illustrates how leaven is hidden in the meal, representing the secretive and diffusive nature of false doctrine that hinders obedience to the truth. This hidden corruption spreads like leaven through dough, breaking up and corrupting the integrity of God's church. The pervasive influence of such false teachings is a powerful force, not originating from Him who calls us, but from adversarial sources seeking to undermine the progress of the church in history.

The unique offering on the Feast of Weeks (Pentecost) serves as a parable that teaches about the Messiah. The two loaves baked with leaven form the centerpiece of this offering, raising a serious question since Scripture universally uses leaven as a symbol of corruption, yet here it appears in a holy day offering. This living lesson introduces a tension that must be resolved to understand the offering. The mystery deepens with the presence of not one, but two leavened loaves, prompting curiosity about the significance of the number two. The priest bakes these wave loaves with leaven, symbolically suggesting that the difference between the two may not be benign, as differences with carnality tend to produce division, if not enmity. This picture presents a puzzle of how God could accept an offering of loaves characterized by corruption.

Leaven serves as a powerful symbol in illustrating the nature and effects of sin. Both honey and leaven, though normally good as food, carry a fermenting and putrefying effect when mixed with flour, teaching us how sin corrupts those who commit it. According to the Interpreter's Dictionary of the Bible, leaven is defined as any substance added to dough that produces fermentation, a process where a fungus breaks down carbohydrates, producing gas that causes the dough to puff up. Honey accelerates this natural process, making them a fitting combination to portray how sin expresses pride and promotes further sin. In the context of sacrificial offerings, the command to exclude leaven and honey underscores that a life of hidden sin, symbolically represented by leaven and honey with its polluting pride, is unacceptable when dedicated in service to God and mankind. Such a life amounts to hypocrisy, which God sees through clearly. During the Days of Unleavened Bread, the physical effects of honey and leaven on flour vividly portray the spiritual impact of sin on a life lived. Jesus Christ expands this understanding by teaching that leaven is not limited to literal acts of sin but includes false doctrine and bad examples. False teaching and poor examples become fertile ground for sin, spreading corruption as they influence attitudes and conduct. He warns to be alert for evil influences, which can stem from various sources in culture, such as traditionalism, skepticism, and secularism, all of which can be anti-God in nature despite any religious façade. These influences impact individuals from a young age, coming from the world through media, peers, and respected figures, making the role of parents crucial in guiding children in the right direction. In the instruction regarding Pentecost, the church is symbolized by two loaves of bread containing leaven, representing the converted under both the Old and New Covenants, still bearing the presence of sin. These loaves, after being waved before God, are not burned on the altar but given to the priests, indicating that God accepts them without consuming them directly. This raises the question of how much leaven, or sin, God allows in the church and in individuals before intervening.

In the Parable of the Leaven, Jesus presents a striking image that would have astonished His listeners. When He likened the Kingdom of Heaven to leaven in bread, it must have seemed almost unthinkable, as leaven typically carries a negative connotation throughout Scripture. Out of 88 mentions, 87 times leaven symbolizes something bad, often associated with sin or corruption. This raises the question of how the Kingdom of Heaven, expected to be glorious and pure, could be full of leaven until it permeates everything. Jesus, looking ahead from His time to His return, saw that the people within the Kingdom would remain full of leaven, representing sin, until they are changed. This reflects the ongoing struggle with human imperfection, even under grace. Leaven, as a symbol, is defined as corruption that multiplies and spreads, much like yeast in dough, affecting the entire batch. Various forms of leaven are identified, such as malice, wickedness, hypocrisy in religion, secularism, and false doctrine, all of which corrupt and hinder obedience to truth. In the parable, a woman takes leaven and hides it in three measures of meal, an amount tied to significant spiritual contexts like fellowship meals and offerings. This act of hiding, with connotations of secrecy and covert action, suggests a deliberate effort to subvert something good. The three measures of meal represent the church's teachings and the service and devotion to fellowman, akin to loving one's neighbor. The parable warns that a false system will covertly attempt to corrupt the true church through false teachings, specifically targeting how members treat one another. The church has often guarded major doctrines well, but its greatest weakness lies in personal relationships, marked by distrust, disunity, and selfishness. These issues strike at the core of the meal offering, symbolizing service and devotion to each other. The warning is clear: false teachings regarding personal relationships are a critical part of satan's plan to undermine the church, and overcoming these relational challenges is essential to align with God's intent.