The objection is this: Isn't it true that there are other means of husbands providing for their families? Why then is financial support necessarily a function the husband should fulfill? Can't the husband provide for his household as a stay-at-home husband and father?
It is certainly true that there are many ways to provide for one's family, but I think the question we are dealing with here is, is it biblical for the wife to function as the primary financial support, while the husband stays at home and functions as the primary manager of the household? Another way of asking this is, Does the financial support role carry more weight than other roles, such that it should be assigned primarily to the husband, the head of the household? I think the answer to the first question is no and second yes. Let me offer some arguments to consider.
The first argument I have is this: That in our culture, financial support is the primary means by which a family is provided its most basic needs. I think we can all agree that without monetary resources, a family cannot survive. Every necessary provision, including clothing, food, and shelter require money to acquire these needs.
Other contributory functions such as teaching or food preparation are also critical for a family's well-being, but these tasks are not essential for providing basic life needs. While very important, a family could survive without them. A family cannot, however, survive without food or clothing or shelter. Teaching and food preparation do little good if the family is struggling with starvation or exposure. Biblically speaking, I think we see this illustrated in Proverbs. For example:
The one who works his land will have plenty of food, but whoever chases fantasies will have his fill of poverty. Proverbs 28:18-20
Here Solomon acknowledges that it is only by working that the basic need of food is provided. No work. No eat. Reading this in tandem with the understanding that the husband is primarily responsible for well-being of his family, I would argue that biblically the task of working to eat falls primarily to the husband.
Consider also this as a supportive passage,
In the same way husbands should love their wives as their own bodies. He who loves his wife loves himself. For no one ever hated his own flesh, but nourishes and cherishes it, just as Christ does the church, because we are members of his body. “Therefore a man shall leave his father and mother and hold fast to his wife, and the two shall become one flesh.” (Ephesians 5:28-31 ESV)
Here the argument is that if the husband, not the wife, is to love and nourish his spouse as part of his own body, the husband is responsible for provision, not the wife. The head, the husband, provides for the body, of which the wife is part. The body does not provide for the head, but rather the head for the body, while providing nourishment and delegating responsibility to the other parts, provides protection of the whole of the body. How can the head nourish the body by asking the body to nourish both itself and the head? Likewise, how can the husband nourish his wife by asking her to function in the primary role of protector and provider of basic needs? I would argue that in the latter scenario, the roles are unnaturally reversed.
So to me the question then is this, should the head of the household, the husband, the stronger vessel, put this heavier and more critical responsibility on the shoulders of the helpmeet, the wife, who is the weaker vessel? If God charges the husband as the protector/superintendent (proistēmi in 1 Timothy 3) of his family, does he fulfill his God-given calling to require of his wife the primary role which most protects and provides for his family's basic needs? In this role the wife, not the husband, becomes the primary protector and caregiver of her family. If she loses her job, the family's survival, at its most basic level, is at stake. To me it is clear then, that in these roles, the husband is no longer serving as the primary protector and caregiver of his family, because the survival of his family at its most basic level is primarily dependent upon the wife.
Consider also the instructions given in 1 Timothy 3 and 5:
In 1 Timothy 3 husbands are charged to proistēmi their households. In 1 Timothy 5 women are charged to oikodespoteō. These are two different words and two different meanings. The first means "rule, protect, care for, and superintend." The second means more "to rule or manage the family affairs." One role is subject to the other. Both share aspects of management, but only one superintends. The husband is specifically charged in chapter 3 with the superintendence, protection, and care of his family. The wife is charged with the management of family affairs, under the superintendence of her husband. How can a husband function as the primary protector and caregiver if his family's protection is dependent upon his wife's employment? If then the protection of one's family is dependent on the wife and not the husband, then I would argue that it is the wife that is primarily protecting the family, not the husband.
A few thoughts on 1 Timothy 5:3-8:
To me it seems that the primary charge to provide for the widow is to the children or grandchildren. This verse does not seem to be specifically addressing the idea of a husband supporting his family financially. Rather, it speaks of children or grandchildren providing for their widowed mothers, and it also seems to teach that members of a household must provide for one another as they are able. But then Paul shifts a bit to talk in the context of households, which in the context of other Scriptures, we know are to be ordered in a specific way. Who is primarily responsible for household provisions? It cannot be the children of the household, nor the wife, who are the weaker vessels. The overall responsibility then falls to the husband, the stronger vessel. The head of the household. Others can help out as necessary, but this too is done under the guidance and leadership of the household's head. The primary responsibility and accountability falls to him.
Another clue we find here is with regard to Paul's instructions for widow care. All references to the unmarried in need are always specific to women without a husband. There is no instruction in Scripture for the care of widowers. Why is this? I believe this is because the responsibility of care and provision primarily falls on the man, the head of the household, and if a man is a widower, he is still the head of his household. A man is expected to work if he is able, as Paul explained to the brothers at Thessalonica when he wrote, "For even when we were with you [brothers], we would give you this command: If anyone is not willing to work, let him not eat. For we hear that some among you walk in idleness, not busy at work, but busybodies. Now such persons we command and encourage in the Lord Jesus Christ to do their work quietly and to earn their own living." (2 Thessalonians 3:10-12 ESV)
Again, Paul charges the men, not the women, with the responsibility of working quietly and earning their own living. This does not mean that a woman is in sin if she conducts business in the household, or even if there is a temporary season where the circumstances require the woman to be the primary provider of income. This may be necessary for the family's survival when the husband is injured or temporarily unemployed. But the husband, as the head, protector, and stronger vessel should feel the weight of that responsibility on him, to get better or find a new job as soon as possible, because God has charged him with the role of protector and caregiver of his wife, who is to be cared for and nourished as part of his own body.
Again, this does not mean that a wife cannot do business or help make ends meet. In some cases, she might even bring in more money than her husband. Proverbs 31 clearly provides an example of a noble and virtuous woman who does a great deal of business and earns income for her family, but notice that the passage does not teach that she is the primary caregiver and protector. Even with women of exceptional entrepreneurial talents, the wife should be able to fall back on the husband should her endeavors fail. If the wife cannot fall back on her husband, then I believe that the husband is not biblically fulfilling his charge to protect and provide for his family's basic needs.