What can people ‘catch’ from you?

Number 567 • September 27, 2020

Matthew 13:33 Parable of the “Leaven”

When we use the word ‘contagious’ or ‘infectious’ we usually think in terms of disease. We take steps to guard against being infected: personal cleanliness and hygiene, diet and exercise, vitamins, antibiotics, and vaccinations to develop personal immunity. We take steps to stop the spread of the disease to others. We wear masks and practice social distancing between ourselves and others. In some cases we quarantine infected persons; they are isolated to prevent them from infecting others. Nobody wants to catch a disease and keep it. If you do catch it you want to be cured from it. Surely you don’t want to give it to others – don’t share it. Has anybody caught anything bad from you?

Good things can be contagious too. Not physically, but morally and spiritually. You’ve probably noticed something in others – a quality or characteristic that you would like to have too. When you catch it, you want to keep it. Perhaps you have something you want to share with others, something you know would be beneficial. Has anybody caught anything good from you? If something is contagious be sure you want to keep it before you “catch” it or share it.


The kind of people one associates with, the situations one involves himself in, and the environment one moves in can determine how he will be affected or infected. All these things can “rub off on you.” It may not be true that “you are what you eat,” but it is true that “you are what you think and what you do” (Proverbs 23:7). You are influenced either to be good or not good by what you allow into your life and fellowship. We often refer to 1 Corinthians 15:33 in warning people about bad companionships. Although the positive principle is not stated in the Bible with regard to good companions, the principle is stated with regard to one’s thoughts and the condition of one’s heart. Phil. 4:6-9

Let us examine both sides, sin and righteousness, then make some applications. Nobody is immune to the infection of sin. If no pleasure could be derived from sin, nobody would do it. The attractiveness of sin and the pleasure derived from it give power and strength to temptation. There is nobody alive who is non posse peccare – “not able to sin.” When sin is committed it produces its irresistible and inevitable effect, wages, fruit, consequence and result, which is spiritual death. Nothing good ever comes from sin (Romans 6:23, James 1:13-15). Love and righteousness can influence others for good, much if not most of the time. Some may have developed a deliberate resistance (a self-inflicted but not natural immunity) to righteousness, a rejection and refusal to accept or share love. But generally a good example inspires others to go and do likewise. A continuing example of righteousness and love in spite of hardship and difficulties inspires others to believe they can keep going too. It is always easier to do what is right and good if you have a positive example. It is easier to love a loving person than one who is spiteful and hateful. It is easier to be cheerful, optimistic, and positive when you are with cheerful people who look on the bright side of things than when you are with sour, negative, gloom-and-doom pessimists. It is easier to be good, think good thoughts, and say good things when you are with good people than it is when you are with people saying and doing bad things. It is easier to enjoy worship when others are enjoying it than it is with those who are going through the motions, but appear to wish they were elsewhere.


The gospel, the doctrine of God in Christ, can and should work like leaven. It should be contagious, passing from one infected person to other susceptible persons. One who receives the gospel, the faith and religion of Christ should not try to contain it, restrict it or restrain it from spreading to others. Instead try to share it so it spreads. The spread of the kingdom is contagious, spreading by influence and contact of one with others. Leaven can be a symbol of either good or not good. In this case it is good – the spread of righteousness. The message of the parable of the leaven in Matthew 13:33 is that there is a leavening power in the gospel that is capable of converting the world. Holiness, happiness, enthusiasm, gratitude, spirituality – Christian faith is contagious. Has anybody caught it from you?

Has the religion of Christ spread from you to any others? Any person can be like leaven in the world – for good or bad. Positive: there is enough power in one Christian to convert the world, if allowed to spread unhindered. Would anybody challenge that? Every Christian has the power to spread the faith, whether he actually does so or not. There should be a helping/healing/converting influence upon others wherever Christians are present (Matthew 5:13-16, Acts 17:6). The positive influence of the Christian should disturb all non-Christians and make them uncomfortable until they too are converted to Christ.

On the negative side, there is enough power in one sinner to pollute, corrupt, and condemn the world if allowed to spread unhindered. Probably nobody would challenge that. Do you know how much negative power there is in just one unhappy, unfaithful, resentful, and disobedient Christian? Enough to disrupt and divide a congregation, enough to make everybody in the church uneasy, dissatisfied, fragmented. Here’s a paradox, a puzzle for you to ponder: A large number of happy, faithful, and properly functioning Christians cannot change one unhappy, unfaithful, or dysfunctional person who does not want to be changed. But just one morally or spiritually defective person can lead many others into misery with him, lead them away from Christ and away from the fellowship of the church. It’s the old “one rotten apple spoils the whole barrel” cliché. If you put one rotten apple in a whole barrel of good healthy ones, what happens? The good apples do not change the rotten one and make it good. The rotten one, if left alone and not removed, will cause the others to rot. The church is a collective entity composed of all its members. The leaven of the church is the composite leaven of all its members. It is amazing how many will challenge this point when we apply it to the church, to the members of the church. “We are human beings, not apples,” they say. “Don’t compare persons to apples.” The fact is, people do not want to feel responsible for what others do, even when they are the cause of it – directly or indirectly. “I don’t care what others think. Nobody has the right to tell me what I can or cannot do. What I do is nobody else’s business.” “Just because I _________ (you can put anything you like in the blank: lie, cheat, steal, drink, smoke, do drugs, commit fornication, abuse people, gossip, use filthy language) doesn’t mean anybody else has to do it.” But like it or not, it is true. If we allow others to sin and make no effort to correct them, then we are indirectly promoting their sin and we should not complain or be surprised the infection spreads to others, perhaps even to ourselves – or when our sins spread to others, friends, family, associates.

In his first letter to the Corinthian church Paul used several examples to show how one person’s improper actions affected the church (1 Corinthians, chapters 5 and 6). One cannot avoid all contact with the sinners of the world – you cannot get out of the world (1 Corinthians 5:9-10). But sin cannot be tolerated in the church. “Don’t you know that a little leaven can leaven the whole lump?” (In this case leaven is a symbol of something bad, the spread of evil). Don’t you know that if you tolerate sin and accept the sinner you will be infected by the sin?” (1 Corinthians 5:6).

What sins was the church facing at Corinth? Immorality, fornication, adultery, homosexuality and sodomy, coveting, idolatry, drunkenness, slander, division, (heresy and denominationalism), extortion, and more (1 Corinthians 5:11, 6:9-10). The fact that Paul addressed two letters to “the saints of God, sanctified in Christ Jesus, along with all the saints in Achaia” (1 Corinthians 1:2, 2 Corinthians 1:1), does not mean that the immoral sinners among them were also saints. Note: one who wants to keep his sin tries to justify it in any way he thinks he can. One must come out of the world and have no fellowship with the sins and sinners of the world in order to be saints of God (2 Corinthians 6:14-17). One must also reject the sins and sinners in the church to maintain a right relationship with God. Have no fellowship with them, do not eat with them, mark them, avoid them and withdraw from them (1 Corinthians 5:11, Romans 16:17, 2 Thessalonians 3:6, 14). The church is supposed to be a hospital where people can be healed from their sins and protected against relapse and reinfection. Some who refuse to give up their sins and refuse to judge themselves or others have misapplied the words of Jesus: “Go learn what this means: I desire mercy, not sacrifice” (Mt. 9:13). Their plea is, “Be merciful to us. Accept us in our sins, in spite of our sins.” But they ignore the part of the verse that says, “I did not come to call the righteous, but sinners to repentance.” If the church becomes a safe haven for sinners, a house of compassion and tolerance for sin and sinners, it ceases to be the church of the Lord and it doesn’t matter how loudly it protests that it is doing what it does in the name of the Lord, Jesus will one day say, “I don’t know you – you have nothing to do with me and I cannot accept you. You and your iniquities get away from me. I will have nothing to do with you.” (Matthew 7:21-23).


Evil can certainly spread like leaven, corrupting susceptible and receptive hearts. “Beware the leaven of the Pharisees, which is hypocrisy” (Luke 12:1, Matthew 23:15). When hypocrisy becomes apparent it brings everything in a person’s life into question and under suspicion. When Paul says “a little leaven can leaven the whole lump” he speaks of a sin or sinner who is allowed to remain in fellowship. One uncorrected sinner can corrupt everybody else; false doctrine can spread from one to another (1 Corinthians 5:6-9, 2 Timothy 2:15-17). There is a personal individual application of this too: unrepented and uncorrected sin leads to more sin, until the conscience is hardened and the person is “past feeling” (1 Timothy 4:1-2, Ephesians 4:17-19). Evil should not be tolerated, not in others and not in oneself. Once the gospel is introduced into one’s life it should be allowed to continue toward perfect completion so it can then spread safely to others. If it is allowed to work the gospel will pervade, influence, and change every area and aspect of the person’s life and being, even his body, soul and spirit (1 Thessalonians 5:23), so that he becomes “a new creature” (2 Corinthians 5:17; compare Ephesians 4:24, 2 Corinthians 3:18, etc). If one wants to be fully Christian he must let the word and will of God have its unimpeded and uninterrupted way in all his attitudes, actions, and relationships until he is fully leavened, completely converted. If one wants to evangelize others he must guard his own life and example as well as what he teaches from the words of God. That is no doubt the way God wants the kingdom and the gospel of the kingdom to work (see Psalm 119:11 “I have hidden thy word in my heart,” and Psalm 19:7-14 “Let the words of my mouth and the meditations of my heart be acceptable in Thy sight, O Lord.”

People can be immune to good things when sin hardens their hearts. There is no way to get good things in without putting the bad things out. If evil is embraced and allowed to remain in the heart, it will eventually overcome and expel the good. There is probably no end to the good impact you can have on the lives of others if you want to, and if they will let you. If you haven’t been following the good examples that are all around, please start now. <><>

#geraldcowan #influence