TL

Good question Mark. Context and culture I think will help. First, in that era a wife and the rest of the household was expected to follow the beliefs of the husband/father. This is why a married woman living with an unbeliever (1 Peter 3) was advised to witness by her behavior and not by her words. Secondly, it is possible that the husband contributed somehow to the wife’s behavior, perhaps by simply doing nothing, just like Adam with Eve. Then it would be proper for Paul to say “if they both continue in faith”.