And if any one know not how to rule his own house [1] This argument, drawn from the less to the greater, is in itself manifest, that he who is unfit for governing a family will be altogether unable to govern a people. Besides that it is evident that he is destitute of the virtues necessary for that purpose, what authority will he have over the people, seeing that his own house makes him contemptible?

Footnotes

1 - "The house of a believer ought to be like a little church. Heathens, who did not know what a church is, said that a house is but an image and figure of any public government. A poor man, living with his wife and children and servants, ought to be in his house like a public governor; but Christians ought to go beyond this. Every father of a family should know that God has appointed him to that place, that he may know how to govern his wife and children and servants; so that God shall be honored in the midst of them, and all shall do Him homage. Paul speaks of children; and why? Because he who wishes to discharge his duty as pastor of a church must be like a father to all believers. Now, let us suppose that a man cannot govern two or three children which he has in the house. They are his own children, and yet he cannot keep them in subjection; they are deaf to all that he says to them. How then shall he be able to govern those who are at a distance, and who may be said to be unknown to him, who even refuse to become wiser, and think that they have no need of being instructed? How shall he be able to keep men in dread when his own wife is not subject to him? Let us not, therefore, think it strange if it is required in all pastors, that they be good fathers of a family, and know what it is to govern their own children well. It is not enough to condemn the children, but we must condemn the fathers, when they permit their children to be worse than others." -- Fr. Ser.

For if a man know not how to rule - This is a beautiful and striking argument. A church resembles a family. It is, indeed, larger, and there is a greater variety of dispositions in it than there is in a family. The authority of a minister of the gospel in a church is also less absolute than that of a father. But still there is a striking resemblance. The church is made up of an assemblage of brothers and sisters. They are banded together for the same purposes, and have a common object to aim at. They have common feelings and common needs. They have sympathy, like a family, with each other in their distresses and afflictions. The government of the church also is designed to be "paternal." It should be felt that he who presides over it has the feelings of a father; that he loves all the members of the great family; that he has no prejudices, no partialities, no selfish aims to gratify.
Now, if a man cannot govern his own family well; if he is severe, partial, neglectful, or tyrannical at home, how can he be expected to take charge of the more numerous "household of faith" with proper views and feelings? If, with all the natural and strong ties of affection which bind a father to his own children; if, when they are few comparatively in number, and where his eye is constantly upon them, he is unable to govern them aright, how can he be expected to preside in a proper manner over the larger household where he will be bound with comparatively feebler ties, and where he will be exposed more to the influence of passion, and where he will have a much less constant opportunity of supervision? Confucius, as quoted by Doddridge, has a sentiment strikingly resembling that before us: "It is impossible that he who knows not how to govern and reform his own family, should rightly govern and reform a people." We may remark, also, in this verse, a delicate and beautiful use of words by the apostle to prevent the possibility of misapprehension. While he institutes a comparison between the government of a family and that of the church, he guards against the possibility of its being supposed that he would countenance "arbitrary" authority in the church, even such authority as a father must of necessity employ in his own family. Hence, he uses different words. He speaks of the father as "ruling" over his own family, or "presiding over it" - προστῆναι prostēnai; he describes the minister of religion as "having a tender care for the church" - ἐπιμελὴσεται epimelēsetai.

For if a man know not - Method is a matter of great importance in all the affairs of life. It is a true saying, He that does little with his head must do much with his hands; and even then the business is not half done for want of method. Now, he who has a proper method of doing business will show it in every affair of life, even the least. He who has a disorderly family has no government of that family; he probably has none because he has no method, no plan, of presiding. It was natural for the apostle to say, If a man know not how to rule his own house, how shall he take care of the Church of God? Look at a man's domestic arrangements; if they be not good, he should not be trusted with any branch of government, whether ecclesiastical or civil.

For if a man know not how to rule his own house,.... Which is an affair of less importance, and more easy to be done; not requiring so much resolution, prudence, care, and thought:
how shall he take care of the church of God? preside over it, rule in it, provide for it, and see that everything is in its proper place, and done according to the will of God. The argument is from the lesser to the greater.

For--Greek, "But."
the church--rather, "a church" or congregation. How shall he who cannot perform the lesser function, perform the greater and more difficult?