Because he was writing to Greek's and Romans and none of them had more than one wife. The only two possible questions are: do they have a wife, and are they still married to their first wife. Just a side effect of his audience.
Are you saying then that we should understand
mia as 'one' because that's what Paul probably thought and didn't need to be super-specific? Or are you saying that Paul may have used
mia not because he was trying to limit men to one wife but because it simply wasn't an issue writing to apostles who were operating in Roman (monogamous) territories?
Just wanted to check because of the way IC's statement you're quoting relates to your follow up. The way I'm reading it, though, looks like another pretty good insight with a lot of explanatory power (although
@IshChayil, let me know if I'm pushing too hard against the grammar here).
Jesus straight up said his mission was not to the unwashed heathens but to the house of Israel, but then he told his messengers he would send them to the uttermost part of the earth. Then this guy Paul comes along, says he's had an encounter with God and he's appointed specifically to be an apostle to those unwashed, uncircumcised types. He recruits his own crew (Barnabas, Silas, Timothy, Titus, Silvanus, etc) and gets to work, preaching and establishing fellowships of converts around the Roman/Mediterranean world, wherever the Spirit leads him.
In that context, he writes a couple of his crew to advise them on how to set up fellowships when he's not around, and one of the qualifications for the men who are going to run things after the messengers leave town is that they should have
mia wife. Paul could have been grammatically more specific if he meant "at least one, but he can have as many as he wants" or if he meant "there can be only one", but he wasn't.
If that situation happened today, we would presumably get the exact same result. Something happens over in the Middle East, news starts to spread, messengers are sent out, letters are written, and I could very easily see a letter being written to a junior apostle working in America that would say 'the men you appoint should have a wife' or even 'one wife' simply because polygamy is just not on the radar in that moment. When the whole culture is based on legally-enforced monogamy, your choices are 'guys with a wife', and 'guys with no wife'.
This circles back to the grammar, because in English our use of articles is different. In other words, if something happened today, Paul would presumably write to an apostle in America in
English (the
koine Greek or
linga franca of the 21st century), so we would
know what he meant, or we could email him back and ask him to clarify, but I digress....
My point is that the fact that Paul's choice of words is to our way of understanding Greek 'ambiguous' may be grounded in the fact that
polygamy was not at issue because of who he was talking to. If he had intended to unilaterally and without explanation
limit men to one wife, he could have said so more clearly. And if he had intended to
promote polygamy, he could have said so more clearly. He simply
didn't say.
So maybe we shouldn't say either. We don't see any evidence that Jesus or any of the Jerusalem apostles
ruled out polygamy for the house of Israel, and Paul does not speak as clearly as he could have to rule it out for Roman-ruled gentiles, he just doesn't make an issue out of it one way or the other. "Let every man be fully persuaded in his own mind."