I wouldn't argue with what you said. The first person I ever heard use the reasoning from 1 Cor. was a Circuit Overseer. Then it was permissable for the Elders etc. to use it, but, it was never a definate assurance that the unbelieving mate would be "saved", only that by the believing mates efforts at being loyal to "Jehovah's Organization", the unbelieving one "might" be saved "who knows"
Borgfree
"Creative minds have always been known to survive any kind of bad training." -Anna Freud
Borg, hahah.... I'm sure the ones married to monsters aren't hoping their faithfulness will be rewarded will an eternity of HELL with the spouse they despise..lol
So they invented a new understanding..
~~~~~~~~~~~~~~~~~~~~~~~~~~~~ "The only good elite are dead elite!!"-Naeblis (Ok! He borrowed it)