As we keep the 2020-21 Holy Day season, we have put leavening out of our homes and are eating unleavened bread for seven days. We have long understood leavening as a metaphor for sin since the fermentation process is symbolic of spiritual corruption, based on what Paul wrote in 1 Corinthians 5:6 1 Corinthians 5:6Your glorying is not good. Know you not that a little leaven leavens the whole lump?
American King James Version×, “Do you not know that a little leaven leavens the whole lump?”
We do indeed know that and rehearse it every year as we keep the Days of Unleavened Bread. However, our observance this year in the United States and many other nations has been subject to restrictions due to the coronavirus pandemic. The silver lining on this cloud hanging over us is that we can learn a vital but largely overlooked lesson about sin that is most relevant to this Holy Day season, namely the pervasive nature of sin and how to help prevent sin from spreading.
This classic statement about leavening appears also in Galatians 5:9 Galatians 5:9A little leaven leavens the whole lump.
American King James Version×, where it refers to the rapid spread of false teachings (see also Galatians 1:6 Galatians 1:6I marvel that you are so soon removed from him that called you into the grace of Christ to another gospel:
American King James Version×). Similarly, Jesus warned His disciples to “take heed and beware of the leaven of the Pharisees and the Sadducees,” which he explained as meaning their doctrine (Matthew 16:6-12 Matthew 16:6-12  Then Jesus said to them, Take heed and beware of the leaven of the Pharisees and of the Sadducees.  And they reasoned among themselves, saying, It is because we have taken no bread.  Which when Jesus perceived, he said to them, O you of little faith, why reason you among yourselves, because you have brought no bread?  Do you not yet understand, neither remember the five loaves of the five thousand, and how many baskets you took up?  Neither the seven loaves of the four thousand, and how many baskets you took up?  How is it that you do not understand that I spoke it not to you concerning bread, that you should beware of the leaven of the Pharisees and of the Sadducees?  Then understood they how that he bade them not beware of the leaven of bread, but of the doctrine of the Pharisees and of the Sadducees.
American King James Version×). The Bible Knowledge Commentary explains, “Their teaching was like pervasive yeast, penetrating and corrupting the nation.”
Paul warned Timothy about the potentially pervasive nature of empty discussions, citing the example of Hymenaeus and Philetus “who have strayed concerning the truth, saying that the resurrection is already past; and they overthrow the faith of some” (2 Timothy 2:14-18 2 Timothy 2:14-18  Of these things put them in remembrance, charging them before the Lord that they strive not about words to no profit, but to the subverting of the hearers.
 Study to show yourself approved to God, a workman that needs not to be ashamed, rightly dividing the word of truth.
 But shun profane and vain babblings: for they will increase to more ungodliness.
 And their word will eat as does a canker: of whom is Hymenaeus and Philetus;
 Who concerning the truth have erred, saying that the resurrection is past already; and overthrow the faith of some.
American King James Version×). He also instructed Titus to “reject a divisive person after one or two warnings” (Titus 3:10 Titus 3:10A man that is an heretic after the first and second admonition reject;
American King James Version×, New English Translation). The lesson here is that swift, decisive action is necessary to protect the congregation before false teachings are allowed to spread.
These passages help us to understand the meaning of Paul’s reference to the blatant sin in Corinth as like “a little leaven [that] leavens the whole lump.”
The context of Paul’s reference to leavening has to do with not just the effect of sin in the personal life of members, but the need to keep sin from affecting the entire congregation, which is what was taking place in Corinth.
“The saying, ‘It takes only a little chametz to leaven a whole batch of dough,’ quoted in a similar context in Galatians 5:9 Galatians 5:9A little leaven leavens the whole lump.
American King James Version×, here tells the Corinthians not only that each individual should guard against personal sin, but also that permitting a promiscuous sinner who professes to be a fellow-believer (see 1 Corinthians 5:9-10 1 Corinthians 5:9-10  I wrote to you in an letter not to company with fornicators:  Yet not altogether with the fornicators of this world, or with the covetous, or extortionists, or with idolaters; for then must you needs go out of the world.
American King James Version×) to remain in their midst is a sure way to infect the entire… community with sin” (The Jewish New Testament Commentary).
The abominable sin of incest was common knowledge among the membership, yet no action was being taken due to the “puffed up” (arrogant) nature of those who were proud of their alleged superior knowledge (1 Corinthians 5:1-2 1 Corinthians 5:1-2  It is reported commonly that there is fornication among you, and such fornication as is not so much as named among the Gentiles, that one should have his father's wife.
 And you are puffed up, and have not rather mourned, that he that has done this deed might be taken away from among you.
American King James Version×; 8:1). So, Paul had to command them to do what they should have done long before (1 Corinthians 5:1-5 1 Corinthians 5:1-5  It is reported commonly that there is fornication among you, and such fornication as is not so much as named among the Gentiles, that one should have his father's wife.  And you are puffed up, and have not rather mourned, that he that has done this deed might be taken away from among you.  For I truly, as absent in body, but present in spirit, have judged already, as though I were present, concerning him that has so done this deed,  In the name of our Lord Jesus Christ, when you are gathered together, and my spirit, with the power of our Lord Jesus Christ,  To deliver such an one to Satan for the destruction of the flesh, that the spirit may be saved in the day of the Lord Jesus.
American King James Version×). Hence Paul’s scolding remark in verse 6, “Don’t you know…” (The New Living Translation reads, “Don’t you realize…”) regarding the pervasive nature of sin. They should have understood and taken appropriate action to protect the congregation by removing the unrepentant sinner from the congregation—which could be understood as spiritual quarantine.
We can better understand the importance of that biblical principle in the context of sin by what we are experiencing in the current battle against the coronavirus pandemic.
It is the pastor’s responsibility to take such action, which can take the form of suspension or excommunication—what we more commonly refer to as disfellowship. However, the fact that Paul blames the whole congregation (you is plural throughout the chapter) is significant. This indicates that although it's a pastor's responsibility to make the decision to disfellowship, the whole congregation has the responsibility to abide by that decision so it has effect. All of the members have an important role to protect the congregation—as well as to hopefully help the sinning person come to repentance.
Similarly, government leaders can only ask or require people to practice “social distancing,” but unfortunately, some have chosen to disregard and fail to carry out this order that is designed to protect all citizens and slow the spread of the virus.
Paul’s admonition to the congregation in Rome could be described as “social distancing” or perhaps “spiritual distancing.” He writes, “and now I make one more appeal, my dear brothers and sisters. Watch out for people who cause divisions and upset people’s faith by teaching things contrary to what you have been taught. Stay away from them” (Romans 16:17 Romans 16:17Now I beseech you, brothers, mark them which cause divisions and offenses contrary to the doctrine which you have learned; and avoid them.
American King James Version×, New Living Translation).
Another factor common to both the coronavirus pandemic and pervasive nature of sin is that even though not everyone is infected, everyone is affected. We must also practice spiritual quarantine to avoid becoming infected with sin. The situation in Corinth wasn’t that there was a danger of every member becoming guilty of incest. But their lack of action was indicative of their overall unhealthy spiritual condition.
Most of the deaths from the coronavirus have been people with pre-existing health conditions. So just as it is important to maintain good overall health (especially a strong immune system), it is also important for us to maintain good spiritual health by a healthy diet of spiritual food. This spiritual food can be the Bread of Life and “meat in due season”—and keeping our hands clean (righteous conduct):
“Who shall ascend the hill of the LORD? And who shall stand in his holy place? Those who have clean hands and pure hearts, who do not lift up their souls to what is false, and do not swear deceitfully” (Psalms 24:3-4 Psalms 24:3-4  Who shall ascend into the hill of the LORD? or who shall stand in his holy place?
 He that has clean hands, and a pure heart; who has not lifted up his soul to vanity, nor sworn deceitfully.
American King James Version×, New Revised Standard Version, emphasis added).
“Draw near to God, and he will draw near to you. Cleanse your hands, you sinners, and purify your hearts, you double-minded” (James 4:8 James 4:8Draw near to God, and he will draw near to you. Cleanse your hands, you sinners; and purify your hearts, you double minded.
American King James Version×, New Revised Standard Version emphasis added).
The New Living Translation puts it this way (emphasis added): “Come close to God, and God will come close to you. Wash your hands, you sinners; purify your hearts, for your loyalty is divided between God and the world.”
The coronavirus pandemic is too widespread and pervasive for one person or even governmental officials and health professionals to defeat. We must all do our part to comply with their instructions and help other people as we have opportunity to do. Other members have helped us by delivering groceries to us, since we must stay home because we are in a high-risk category due to our ages. Most importantly, we need to pray for God to protect and deliver us from this pandemic.
This is the same way we prevent the pervasive nature of sin. Just as governmental officials and health professionals are the best resources to determine what must be done to battle COVID-19, we must follow the instructions and guidelines given by our church leaders and local pastors on how to apply biblical principles in our battle against the spread of sin. Just as not all illnesses are contagious, neither are all sins pervasive. That is their responsibility to make that determination; it is our responsibility to do our part in the battle against sin (Hebrews 3:12-13 Hebrews 3:12-13  Take heed, brothers, lest there be in any of you an evil heart of unbelief, in departing from the living God.
 But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin.
American King James Version×; 12:14-15).
Christianity has experienced numerous spiritual epidemics and pandemics, as has our church culture. So, let’s be sobered by and learn from the COVID-19 pandemic in our battle against sin, especially this time of year as we focus on the lessons we must learn from the Days of Unleavened Bread.
“Therefore let us keep the feast, not with old leaven, nor with the leaven of malice and wickedness, but with the unleavened bread of sincerity and truth” (1 Corinthians 5:8 1 Corinthians 5:8Therefore let us keep the feast, not with old leaven, neither with the leaven of malice and wickedness; but with the unleavened bread of sincerity and truth.
American King James Version×).