For what knowest thou, O wife...? — This verse has been very generally regarded as a kind of modification of the previous one, as if the Apostle suggested that it might be advisable not to let the unbelieving partner depart from the marriage union when he so desired, in any case where there was even a chance of the believing partner effecting his or her conversion. The true meaning of the passage is, however, precisely the opposite. The Apostle declares that the remote contingency of the unbeliever’s conversion is too vague a matter for which to risk the peace which is so essential an element in the Christian life. If the unbelieving partner will depart, do not let any thought as to the possible influence you may exercise over his religious convictions — about which you cannot know anything, but only at most vaguely speculate — cause you to insist upon his remaining.
Some historical results, arising from the view that this is a suggestion of the good which may result from such union being continued, are interestingly alluded to by Stanley in his note on this passage: — “This passage, thus interpreted, probably had a direct influence on the marriage of Clotilda with Clovis, and Bertha with Ethelbert, and consequently on the subsequent conversion of the two great kingdoms of France and England to the Christian faith.”