When Peter begins to address wives in the congregation, his focus is on how the outsiders understand the Christian wife. The situation in view in 3:1 is of a wife who has come to Christ, but her husband is not a Christian. While there are many examples of this sort of thing in our modern experience.
In the Roman world, the wife is expected to adopt the gods of her husband’s family when she marries. The same would be true of a Jewish family, although it is less likely that a Jewish man would marry a Gentile woman. In either case, the ancient world did not really have religiously “mixed marriages.” If a husband became a believer, then the Roman world would have expected the wife to also convert. It is possible that a husband converting was not as socially disruptive as a wife.
Like the slave, the wife is to have respectful and pure conduct so that an unbelieving husband may believe (v. 2). The same language is used for the wife as for the slave (ὁμοίως, likewise). This does not mean that the woman is socially like a slave, but within the Greco-Roman or Jewish household, the wife did in fact defer to the husband.
Peter has already commanded the reader s to live honorable lives so that the Gentiles will see and honor God (1 Peter 2:12), but here he narrows the application to a believing wife who is under the authority of her husband.
The goal of this respectful behavior is missional. Perhaps the husband will be “won” to Christ. This is a common way for modern evangelicals to express evangelism, but the use of this verb (a future passive form of κερδαίνω) is unique in the New Testament.
As Karen Jobes points out, if a woman began to worship Jesus and reject her husband’s family gods, she would be in a socially dangerous position (1 Peter, 202-3). Both Greco-Roman and Jewish society would see this as a kind of rebellion against proper family values. Since she is rejecting the family gods, she would be seen as a rebellious wife, and perhaps could be seen as a kind of “home-wrecker.” The husband could potentially find himself in socially embarrassing situations. A wife that rejected the community gods would be a shame for the husband to bear.
Attendance at Christian worship would mean that the wife had social connections outside of her husband’s friends and family. This too was a strange behavior in that culture and would be viewed suspiciously by Romans or Jews. This would be the case for a Jewish woman as well, especially if Jewish followers of Jesus were being persecuted in the synagogue.
To avoid the appearance of rebellion, the godly wife should strive to maintain a true, “imperishable” beauty (3:3-4). For the most part there is nothing unusual about this description of true beauty even in the Greco-Roman world. Similar statements are made in secular Greek concerning modest dress and appropriate adornments. The principle is modesty; a woman would not want to be confused with a courtesan!
The temperate, freeborn woman must live with her legal husband adorned with modesty, clad in a neat, simple, white dress. . . She must avoid clothing that is either entirely purple or is streaked with purple and gold, for that kind of dress is more by a hetarae (courtesan) when they stalk the masses of men . . . You should have a blush on your cheeks as a sign of modesty instead of rouge, and should wear nobility, decorum and temperance instead of gold and emeralds. (Pseudo-Melissa, Letter to Kleareta, 160-162, Witherington, Letters and Homilies, 2:164)
True beauty is a gentle and quiet spirit, not unlike the woman described in Proverbs 31. In contrast, the woman who has an obnoxious, loud spirit will not be a good witness to her unbelieving husband.