Actually I'm not sure it is as clear as some people would like it to be. The verses in 1 Timothy 3:2 and 3:12 say literally that the overseer and the deacon should be "a one woman man" μιας γυναικος ανδρα. In helping us understand what this means we can look to 1 Timothy 5:9 where it tell us about what qualifies a widow to get her put on the widow list. Here Paul writes that she must be "a one man woman" ενος ανδρος γυνη which is the exact opposite of what is said about the overseer and the deacon. Polyandry was not a practice at that time and so the text is generally interpreted that she must not have been divorced. It makes most sense that the earlier verses of 3: 2, 12 actually are saying that the overseer and deacon should not be divorced. Furthermore, polygamy was not a Greek custom at that time so it makes no sense for Paul to address it as an issue.
I still have yet to find a verse in the Bible clearly speaking against polygamy. The usual arguments require wrestling with verses that do not even address the issue.
this response would go to dayhiker as well.
The issue in Jesus' divorce teachings is that it is considered adultery for a person to remarry after a divorce. If you are permitted to have more than one wife, marrying a new wife should not be considered adultery, but it is.
Notice that Jesus isn't talking about merely having sex with a woman that your not married to, he's talking about marrying another woman.
If you are allowed to marry more than one woman, then remarriage after divorce should be allowable, but it isn't.
Thus it is pretty clear that to marry more than one woman is adultery according to God's intent for marraige. God allowed it in the past, just as he allowed divorce under the law of moses.
Going on to the timothy passages, your arguments here don't help your case. Whether you interpet the passage to say "husband of one wife" or "a one woman man" it doesn't change the fact that you can only have ONE WOMAN. There is no way you can logically argue that a man with 5 wives is a one woman man.
What you point out doesn't allow for polygammy, what it does is disallows divorce.
If anything, the point you made about the translation of "one woman man" and "one man woman" stresses the sanctity of the union between one woman and one man.
Think about it this way. If Paul had wanted to say "you can only be married to one woman" he could have said so. If he had wanted to say "you can not have been divorced" he could have said that also in no uncertain terms. What he did was effectively say both in one phrase.. you must be a one woman man.