The saying is trustworthy: if anyone is eager for supervisory authority, he longs for a good work. Thus the supervisor must be unconvictable, husband of one wife, sober, temperate, orderly, hospitable, instructive, not drunken, not brawling, but equitable, uncontentious, unavaricious, presiding well over his own household, keeping children well-ordered with every kind of honor -- for if one does not preside over his own household, how will he take care of the church of God? -- not inexperienced, so that he has not been clouded so as to fall into the judgment of the devil. And also he must have a good witness from those outside, so that he might not fall into disgrace and the trickery of the devil.
[1 Timothy 3:1-7, my rough translation. 'Supervisor', like 'overseer', is the literal translation of episkopos, or 'bishop'. As always, I translate this hyperliterally so that we not forget that 'bishop' is not mere jargon but says what the point of the office is. Philoxenon, hospitable, literally means 'fond of guests', but is a fairly broad term (and a very revered character trait) in the ancient world; it's very difficult to convey the strength of the word in English, because we do not generally treat hospitality as a literally sacred value associated with divine things, which it was in the ancient world. It's tempting to see nephalion (sober) and sophrona (temperate) as concerned with the internal qualifications and philoxenon and didaktikon (instructive) as the external outflow of these, with kosmion (orderly) being the mediating term between the internal and the external. If this is the case, then the series is not just a list but gives a profile or template of the properly lived episcopal life.
Paroinen (drunken) means 'given to (literally: staying near) wine' but can also be used more broadly for the kinds of behaviors that are associated with people given to drinking -- quarrelsomeness, erratic behavior, etc. Plekton (brawling) literally means hitting, striking, punching, and that sort of thing.
Aquinas in his commentary takes the clauses between 'instructive' and 'presiding well' to rule out three major areas of temptation, concupiscence of flesh, anger, and cupidity, which is, I think, at least in the ballpark of what St. Paul has in mind here. His discussion is somewhat complicated by the fac that the Latin translator seems to have had some difficulty conveying the Greek meaning into Latin, given that the closest Latin terms overlap the Greek terms in meaning but not always well. The Latin is: Oportet ergo episcopum irreprehensibilem esse, unius uxoris virum, sobrium, prudentem, ornatum, pudicum, hospitalem, doctorem, non vinolentum, non percussorem, sed modestum: non litigiosum, non cupidum (Therefore it befits the bishop to be irreproachable, man of one wife, sober, prudent, decorous, chaste, hospitable, a teacher, not winebibbing, not a hitter, but modest; not contentious, not covetous). That's thirteen terms in Latin to cover twelve terms in Greek. The Latin translation seems to translate sophrona as 'prudent' rather than 'temperate' to distinguish it from 'sober' (they indeed can overlap, creating a question of how they are supposed to be distinct), and to translate kosmion by two words, 'decorous' and 'chaste', which is a (reasonably plausible) interpretation of the kinds of orderliness meant by the Greek word. Modestum as a translation of epieike (equitable/fair/flexibly rather than rigidly just) is not bad -- the Latin modestum, unlike its more parochial English cognate, has a very large range of meaning -- but precisely because of the large range obscures the connection with epieikia (equitableness), which actually seems quite important. Seeing it sandwiched between 'not a hitter' and 'not contentious', Aquinas takes modestum to mean 'patient' -- which, again, is arguably in the ballpark of what is meant, because he is probably right that it is carrying through rather than disrupting the line of thought. 'Evenhandedness' or 'fairmindedness' might capture the point, someone refusing to jump easily into fights because he is always trying to be fair to people. I mention all this because it is a good example of the kinds of things that have to be considered in trying to translate a list that is not given much of an explanation.
The 'take care of' (epimelesetai), which parenthetically seems to sum up the entire episcopal task, is elsewhere in the New Testament only found in the parable of the Good Samaritan, where it is found twice; the Good Samaritan, having tended the beaten traveler with oil and wine, loads him onto his own beast, and then takes him to an inn to take care of him; when he leaves, he gives money to the innkeeper and tells him to take care of the traveler. Of the two dangers to the bishop mentioned in verses 6 and 7 (the first internal and the second external), being 'clouded' (typhotheis), is more often translated as 'puffed up', which is in some ways an excellent compromise as a translation. The word literally means 'smoke-filled' or 'cloudy', but very often has the figurative sense of 'arrogant, proud, vain'. Oneidismon (disgrace) literally means 'insult' or 'blame' and is often translated as 'reproach' or 'reviling'; it does not, however, necessarily imply that the insult or blame is justified, and I am inclined to think that here it is unjustified blame that is in view. The inexperienced (neophyte) bishop can fall into the power of the devil through pride, but even unjustified accusation can be used by the devil to neutralize the effectiveness of a bishop, so the kind of person who should be bishop should be someone who has real experience in matters of spirit (avoiding the temptations of pride) and in matters of public interaction (avoiding the trap of situations that bring unnecessary disrepute on himself and his flock).]