Great paraphrase and final paragraph summary. I think you’ve captured it.

Apparently children with two unbelieving parents are “unclean”, while those with at least one believing parent are “holy”. It seems the children, like the unbelieving parent, are sanctified by the believing partner. Therefore, if the believer should fall away, the holy children would become unclean.
There must be an explanation in the application of the words “sanctified”, “holy”, and “unclean”.

Since Paul is writing to Gentiles to whom he has taught freedom from Mosaic law, the word uncleanness, in this instance, would not seem to refer to a ceremonial defilement, unless it were a disqualification for a Christian baby dedication ceremony in which unsaved people might be unwelcome. Even in such a case as that, must we not suffer the little children to come unto Jesus?

Since the word “sanctified” means “set apart” as “holy” for sacred use and /or for blessing, consider this paraphrase:

For the unbelieving husband is blessed by the wife, and the unbelieving wife is blessed by the husband: else were your children unblessed; but now are they blessed.

In other words, protective, material and familial blessings fall upon the family of one believing parent as the goodness of God leads the unbelievers toward repentance.

Bob Lyle

Yes, this can be a little misleading. The answer is basically saying that the child would not be living in God’s presence unless one of the parents were a Christian. The answer to “Had I died as an infant, would I have been unable to come into the presence of God?” is no, you would not have been unable to go into the Lord’s presence. We believe children who die before the age of accountability do go into the Lord’s presence. Thanks for the comment. Because we are using short answers to these complex questions, inevitably other questions will arise.

I was born to unsaved (and unwed) parents. Had I died as an infant, would I have been unable to come into the presence of God? I think I know the answer, but I wonder if readers might be misled?