Richard Ritenbaugh, citing Francis Shaeffer's observation, that bitterness rather than doctrine divides and estranges one member from of Christ's Body from another, suggests that individuals often look for a 'doctrinal' reason to cover up the real reason for leaving a congregation. Perhaps the principal cause of the estrangement between brethren can be explained by the Parable of the Leaven in Matthew 13:33, an image of a process of exaggerated growth, parallel to the mustard see analogy, in which a garden plant unnaturally grows into an imposing tree. Although many Bible Commentaries have assumed that both of these similes simply mean what started small will grow to something large, they fail to take into account the necessity of symbols remaining consistent beginning with the first mention in scripture. Leaven symbolizes corruption from sin, even as we examine the wave loaves, composed of humans laden from sin (from which they have repented). As ambassadors for Christ, already having our citizenship in Heaven, we still have sin in our nature. Interestingly, the grain offering in Leviticus 3, designated for the peace offering or fellowship offering did not contain leaven. As a biblical symbol, leaven stands for hypocrisy, false teachings, sexual immorality, vile corruption, malice and wickedness, a condition which will not exist in God's Kingdom, but is rampant in the Church of God today as it syncretizes doctrine with 'knowledge' derived from the Babylonic worldly philosophies. The woman sneaking in the leaven with three measures of meal in Matthew 13 evidently represents the Church, who surreptitiously mixed Christ's pure doctrine with a little sourdough of worldly wisdom, puffing up the church with intellectual vanity, but destroying the prospects of unity or reconciliation between the numerous splinter groups. With this leavening, Satan has destroyed the relationship between church members by corrupting the doctrines that had bound us together.
John Ritenbaugh, reflecting on Jesus Christ's prayer for unity in John 17, insists that unity with our brethren is impossible without unity with God first. Adam and Eve severed this unity by yielding to Satan's influence, stimulating their minds with a novel diversion. Sin automatically separates us from God. The key to overcoming rests exclusively in our relationship with God. We are placed in the Body of Christ at His discretion, and are obligated to subject ourselves to His workmanship, keeping Him continually in our thoughts, night and day. We do not produce any fruit unless we are attached to the vine. As members of Christ's body, we must function for the good of the whole body, not competing with other organs or limbs. We must continually see God and function as a son of God. As with our Elder Brother, if we do those things that please our Heavenly Father, He will be there for us. Not responding to God and treating our brethren shabbily, brings harsh judgment upon us. Unity in the Body is brought about by yielding to and using the love of God shed abroad in our hearts, enabling us to love our brother as God has loved us. The more we have in common, the greater will be unity and peace.
John Ritenbaugh asks the question, "How much leavening would God allow to infiltrate into the church, society, or the individual before He steps in to correct it?" Leaven can symbolically represent false teaching, as in the stifling traditions of the Pharisees, the skepticism of the Sadducees, and the secularism of Herod, all producing deadly cynicism and pessimism. With immense forbearance and patience, God carefully timed the cumulative wickedness of a people (when every thought would become saturated with evil) before He intervened. Likewise, we have no insight as to how much sin God will tolerate in the church or our own lives before He will sternly intervene. The tares and wheat (sin and righteousness, heresies and truth, or unconverted and converted) must coexist until the harvest when the fruit will become clearly seen, at which time a separation and judgment will take place, when the good will be contrasted from the evil. In the meantime, the persecution we receive now will show God definitively where our loyalties lie.