(9) A little leaven . . .--A pregnant expression, which leaves a good deal to the reader to supply. The proverb is true which says that a little leaven leavens the whole mass of dough. And so, in your case, the malcontents may be few, but they will soon ruin the whole Church. It seems decidedly more in accordance with the context to take the "little leaven" as referring rather to a few seceders than to a little bad doctrine.

Verse 9. - A little leaven leaveneth the whole lump (μικρὰ ζύμη ὅλον τὸ φύραμα ζυμοῖ); a little leaven leaveneth the whole kneading. This proverb is cited again in precisely the same words in 1 Corinthians 5:6, with the words prefixed, "know ye not that." In both passages the leaven is an element of evil, and so also in Matthew 16:11; but our Lord applied it also to an element of good, which was to penetrate (apparently) the whole mass of humanity (Matthew 13:33). What has the apostle precisely in his view as the leaven in the present instance? In 1 Corinthians 5:6 it is unchastity, which, if once tolerated in a Church, especially amid so licentious a population as that of Corinth, would be but too likely to impregnate balefully the sentiment of the whole community. And here likewise, as there, the leaven does not appear to denote, as some have supposed, the individuals in whom some noxious element was conspicuous, but that noxious element itself; namely, to judge from the colouring of the immediate context, the "readiness to hearken" to" another gospel," which was promising comfort and sense of acceptance, more or less, in the practice of at least some of the outward ordinances of Judaism. This leaven had already begun to work, embodying itself in the observance, pedantically and ostentatiously, of the days and feasts of the Jewish calendar (Galatians 4:10). Now, a movement of mind manifesting itself in some form of external religionism, when once it begins to show itself in a Christian community, has a great tendency to spread. For always, in every Church, there are unstable souls, too often not a few, never able to come to the knowledge of the truth; which have never truly discerned Christ's all-sufficiency for their spiritual needs, or have lost any superficial persuasion of it once enjoyed; and which, consciously unsatisfied with what they as yet possess, and nevertheless only toying with spiritual things, are ready to adopt almost any novelty of religious behaviour offering itself for their acceptance. The particular form in which the external religionism of seekers after another gospel clothes itself varies according to varying tastes or circumstances. Among the Galatian Christians such persons were now beginning to feel attracted by that venerable kind of outward piety exhibited by devout or professedly devout Jews; but in their own practice committing the fatal blunder of mistaking the external shows of saintliness for the reality of saintliness, and but too willing to make the former serve in lieu of the latter. The danger of the leaven spreading was, in the present case, increased by the instability of character and the quick impulsiveness belonging to the Celtic temperament. The true antidote to this "leaven" is in every age the same; namely, that which the apostle in this Epistle strives to administer - the gospel of the righteousness and Spirit of Christ crucified.

5:7-12 The life of a Christian is a race, wherein he must run, and hold on, if he would obtain the prize. It is not enough that we profess Christianity, but we must run well, by living up to that profession. Many who set out fairly in religion, are hindered in their progress, or turn out of the way. It concerns those who begin to turn out of the way, or to tire in it, seriously to inquire what hinders them. The opinion or persuasion, ver. 8, was, no doubt, that of mixing the works of the law with faith in Christ in justification. The apostle leaves them to judge whence it must arise, but sufficiently shows that it could be owing to none but Satan. It is dangerous for Christian churches to encourage those who follow, but especially who spread, destructive errors. And in reproving sin and error, we should always distinguish between the leaders and the led. The Jews were offended, because Christ was preached as the only salvation for sinners. If Paul and others would have admitted that the observance of the law of Moses was to be joined with faith in Christ, as necessary to salvation, then believers might have avoided many of the sufferings they underwent. The first beginnings of such leaven should be opposed. And assuredly those who persist in disturbing the church of Christ must bear their judgment.A little leaven leaveneth the whole lump. A proverbial expression pretty much in use with the Jews; see 1 Corinthians 5:6, respecting either persons or things; and is in answer to, or prevents an objection that might be made, or something that might be said, in favour of these churches; that their case was not so bad, or the danger they were in so great, as was represented by the apostle; since they were only a few persons that propagated this notion, and but few that received it, at least thoroughly gave into it; and that, if it was an error, it was but a small one, and only regarded a single ritual, or a few rituals of the law; to which the apostle replies, by supposing, but not granting this to be the case, since they were pretty generally declined, and the error was not a slight one, that as a little sour leaven influences and ferments a large mass, or lump of dough, and makes it of the same nature with it, so a small error in doctrine, as it may be thought to be, increases to more ungodliness, and eats as doth a canker; and though a few hands may be first concerned in propagating it, and but few be infected with it, yet these may soon spread the contagion through the whole society: wherefore errors and false teachers should be nipped in the bud, and stopped in their beginnings, how inconsiderable soever they and their tenets may be judged to be.