Disclaimer: I am not a linguist.  But I know (mainly through their writings) a number of people who are.  So, obviously, I am relying heavily upon their expertise in what follows.

1 Cor 6:9-11 ‘Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived! The sexually immoral, idolaters, adulterers, passive homosexual partners, practicing homosexuals, thieves, the greedy, drunkards, the verbally abusive, and swindlers will not inherit the kingdom of God.  Some of you once lived this way. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God.

See also:

1 Tim 1:1:8-10 We know that the law is good if someone uses it legitimately, 1:9 realizing that law is not intended for a righteous person, but for lawless and rebellious people, for the ungodly and sinners, for the unholy and profane, for those who kill their fathers or mothers, for murderers, 1:10 sexually immoral people, practicing homosexuals, kidnappers, liars, perjurers—in fact, for any who live contrary to sound teaching.

The words translated in the NET Bible as ‘passive homosexual partners’ and ‘practicing homosexuals’ are ‘malakoi‘ and ‘arsenokoitai‘, respectively.

The difficulty of translation is evidenced by the range offered in various English versions:

AV – “effeminate” and “abusers of themselves with mankind”
NRSV – “male prostitutes” and “sodomites”
NAB – “boy prostitutes” and “sodomites”
NIV – “male prostitutes” and “homosexual offenders”
CEB – “both participants in same-sex intercourse”
TEV – “homosexual perverts”
NLT – “male prostitutes” and “homosexuals”

‘Malakoi‘ is a word borrowed from Latin meaning ‘soft’.  The NET translation is supported by Schreiner.

‘Arsenokoitai‘ is a compound word, not attested before Paul, and used just once more by him (1 Tim 1:10, also in a ‘vice list’).  Its two elements mean, literally, ‘man’ and ‘bed’.  It seems likely that Paul coined the term based on the LXX text of Lev 18:22 and Lev 20:13, where both parts of the compound are used (so Schreiner and others).

We can dismiss without much ado the opinion represented by this blogger, who claims that this verse is routinely and grossly mistranslated.  She writes:

‘In ancient times, the insult of “soft” was hurled at men for a variety of infractions, like wearing perfume or luxurious clothing, not wanting to work, or loving women too much. Yep – loving women too much, or wanting to have sex with a woman “too” often could get a man labeled “soft.” Sure, there were plenty of men who were “soft” who also engaged in same-sex acts, but a look into history shows that not all of them did…How we got from “soft” to “men who have sex with men” just shows how much damage can be done by people who don’t understand context.’

I’m not sure that ‘context’ has much to do with it in this instance, and, in any case, this opinion is offered without evidence, and the second word ‘arsenokoitai‘ is completely ignored.

Actually, there is a near-consensus that this pair of terms are best regarded as representing the passive and active partners in a homosexual relationship.

According to the Dictionary of Scripture and Ethics, art. ‘Homosexuality’,

‘A literal translation would be something like “soft people” and “men who go to bed,” though clearly something far more colloquial is meant—perhaps “male prostitutes and the men who hire their services”?’

NIV (1984) – ‘male prostitutes…homosexual offenders’ (implying that Paul was referring, not to all homosexual practices, but to those that were considered deviant or abusive).

NIV – ‘men who have sex with men’ (adding, in a footnote, that these words ‘translate two Greek words that refer to the passive and active participants in homosexual acts.’)

Barrett: ‘The passive and active partners respectively in male homosexual relations.’

Fee (rev. ed.) holds as a ‘best guess’ that the first word word means ‘”male prostitute” (in the sense of “effeminate call-boy”‘).  This opinion is based on the more definite meaning of the second term, that ‘almost certainly refers to male homosexuality, especially to the active partner.’

Garland:

‘Males who are penetrated sexually by males’ and ‘males who sexually penetrate males.’

Garland forthrightly refutes those (such as Boswell, Scroggs and D. Martin) who do not find here, or in the early church generally, a condemnation of homosexual acts.  But, for Garland,

‘much of this attempt to recast the traditional link of these words to male same-sex eroticism appears to be driven by special pleading and riddled with obfuscation.’

Gagnon offers five reasons which ‘establish that Paul used malakoi, literally “soft men,” in the sense of “effeminate males who play the sexual role of females” (Gagnon 2001a, 306-12):

a. Its placement in the midst of other terms that refer to participants in illicit sexual intercourse.

b. Its position in the vice list immediately before the term arsenokoitai, which clearly refers to the active homosexual partner.

c. The severe penalty imposed for being a malakos (exclusion from the kingdom of God), which suggests a form of effeminacy well beyond the stereotypical limp wrist (contra Martin 1996, 124-29).

d. The use of cognates by Philo of Alexandria to describe men who actively feminize themselves for the purpose of attracting other men (N96).

e. The use of the comparable Latin term molles (“soft men”) in tandem with other terms that refer to effeminate males desirous of penetration by men: the cinaedi (Gk. kinaidoi, lit., “butt shakers”) and pathici (“those who undergo [penetration]”. These designations were not confined fined to adolescents or cult prostitutes, much less did they imply coercion. In fact, they applied especially to adult males who willingly-whether by innate orientation or to great efforts to feminize their bodies, dress, and manner in order to attract men and thus eradicate the masculine stamp given by nature.

(Robert A. J. Gagnon. Homosexuality and the Bible: Two Views (Kindle Edition.)

Fee explains that the very vulgarity of the word (the ‘koitai‘ part is slang for ‘intercourse’) accounts for its rarity in ancient literature.

Fee concludes his discussion of the meaning of these words by noting that

‘for Paul’s attitude towards homosexual practice in general, one need refer only to his own Jewish background with its abhorrence of such, plus his description of such activity in a later letter (Rom 1:26f).’

Loader:

‘The balance of probability favours seeing here a reference to the active and passive participants in same-sex relations’ (Two Views on Homosexuality, the Bible, and the Church, p34).

Barrett is of the same opinion.

Ciampa & Rossner understand these terms as referring to

‘those who willingly play the passive and active roles in homosexual acts.’

Vang concurs, defining the two relevant words as follows:

‘(1) Malakoi means those who are “effeminate” or “soft” and usually refers to men or boys who are sodomized by other males (the passive partners in same-sex relationships). (2) Arsenokoitai refers to the active partners in same-sex relationships (cf. Lev. 18:22; 20:13; LXX uses arsenos).’

Ciampa & Rossner continue:

‘Paul is not discussing “homosexuals” per se, but homosexual acts (commonly engaged in by Roman men who were also active in heterosexual relationships). In the Roman world, homosexual relations were invariably exploitative relations between men of quite contrasting social statures. It was not uncommon for married men to practice heterosexual sex with their wives (and female slaves and prostitutes) and to also engage in homosexual relations with male prostitutes or slave boys or other young men of lower class who had little freedom to refuse. Romans did not think in terms of sexual orientation or identities, but that proper masculinity was to be expressed in taking the active, dominant role in any sexual act. To desire or willingly play a passive homosexual role was considered shameful, but it was expected that men of stature would penetrate people of lesser status (whether women or men) but not be penetrated themselves. The Jewish and Christian perspective affirmed by Paul was quite different.’

Instone-Brewer asserts, with Rom 1 in mind, that

‘we can’t argue that Paul referred only to homosexual rape like that at Sodom, because he condemns both those who penetrate and who are penetrated (arsenokoitēs and malakos, respectively, in 1 Cor 6:9).’ (Moral Questions of the Bible, p87)

It has been argued that these terms describe pederasty:

‘Since this vice list was written to Gentile Christians in Corinth, these dual terms would be recognized as a description of pederasty, which was commonly practiced in Corinth; and this is why Greek lexicons define malakoi as a ‘catamite’ and arsenokoitai as a ‘pederast’, respectively. The most common known examples of pederasty were Romans officers and officials (pederasts) who purchased boy slaves (catamites) for sexual intercourse, and the boys were often procured through temple prostitution, and these officials kept them as personal sex slaves, somewhat like sex trafficking today. For instance, the Centurion’s relationship to his beloved sick boy slave (Luke 7:1-11; Matt 8:5-13) is often identified as a pederasty relationship, and this is an important connection, due to the grace that Jesus extended to the Centurian (pederast) and his young boy slave whom he loved (catamite) (c.f. Luke 7:6).’

Continued:

‘It is difficult to say whether 1 Cor 6:9-11 refers to homosexuality at all, due to the obscurity of the words malakoi and arsenokoitai, and if any particular homosexual prohibition is made in it, then it is most likely prohibiting both passive (catamite) and active (pederast) partners from practicing pederasty, and therefore a general prohibition of all forms of homosexuality cannot be clearly or certainly proven by this text alone.’

Michael Pahl, noting that Paul’s teaching here reflects that of Lev 18:22 and Lev 20:13, use his understanding of those texts to inform his understanding of the present text – namely, that the issue is with male-male sexual relations that are ‘idolatrous or exploitative in nature’.  But since his reading of the Leviticus texts is not wholly convincing, then his interpretation of the present texts is equally dubious.

Thiselton notes that Paul’s teaching here should probably not be limited to abusive homosexual relationships:

‘Many…argue that abusive pederasty was the standard form in which Paul encountered male intimacy. But Wolff shows that this is far from the case. Paul witnessed around him both abusive relationships of power or money and examples of “genuine love” between males.’

It is reasonable to understand this passage as referring to all forms of male homosexual behaviour (and, by implication, female homosexual behaviour).  So Blomberg:

‘It is…linguistically invalid to limit the type of homosexual behavior Paul describes either to pederasty (adult men with underage boys) or to homosexual prostitution (casual sex for profit between individuals not committed to a lasting relationship with each other).’

Blomberg observes that the claim of some homosexual people that ‘God made me that way’ must be rejected.  If there is a genetic predisposition to homosexuality, then this no more excuses homosexual behaviour that, say, a genetic predisposition to alcoholism or to aggression excuses an alcoholic or violent lifestyle.  On the contrary, those who are predisposed in such ways may need to imposes more severe restrictions on themselves (such as total abstention from alcohol).

Blomberg continues:

‘None of this is to deny that conservative Christians have often treated homosexuals far more abusively than they have other sinners. There is real discrimination against the gay community that must be fought—for example, restricted employment opportunities for jobs in which sexual behavior is irrelevant. There is genuine homophobia (fear of association with homosexuals, not merely opinions about their moral condition), especially in our churches. But the “politically correct” movement has often grossly exaggerated the extent of that homophobia and incorrectly applied that label to believers who are lovingly and compassionately trying to uphold biblical standards.’

And again:

‘As in Romans 1:24–27, homo- and heterosexual sins are paired in a way that suggests that neither is any better or any worse than the other. One can scarcely use these verses to claim that no one can simultaneously be a Christian and engage in homosexual actions unless one is prepared to say the same thing of one who commits adultery or exhibits greed!’

Blomberg further urges that we should see this as a real, and not a hypothetical, warning:

‘Like 3:16–17, verses 9–11 must be seen as a real and not merely hypothetical warning. Verse 11 suggests that Paul does think a majority of the Corinthian church is really saved, but there would be no point in his twofold affirmation that the wicked will not inherit the kingdom (vv. 9–10) if he did not fear that at least a few in his congregation might be masquerading as believers.’

Schreiner agrees that this passage refers to both active and passive partners in a homosexual relationship (and not to cases of abuse or pederasty).  He notes that in Lev 20:13 both partners are considered equally guilty.

Prior invites us to consider both the seriousness of God’s prohibition of same-sex sex, and also the factors that might mitigate the guilt of one or both parties:

‘A person is significantly affected by his environment, his heredity, his circumstances, his treatment by others (notably his parents) both as a child and as an adolescent.’

Prior cites the example of black South Africans, among whom homosexuality was virtually unknown in pre-aparthied times:

‘With the institutionalization of apartheid legislation, which compels African men to move to large industrial cities to seek work, vast all-male building complexes have sprung up in ugly urban sprawls like Soweto near Johannesburg and Langa near Cape Town. Men are not allowed to bring their wives and families with them into these ‘townships’ and are forced to leave them behind in the ‘homelands’. Men, therefore, outnumber women in places like Soweto and Langa in the proportion of at least 10 to 1.’ (Prior’s book was published in 1985).

One of the results of this has been the growth of homosexual practices among the black South African population.

We must therefore, concludes Prior, assert both the responsibility of each of us for his or her own actions, and also the wise judgement of God, who is well able to take full account of motives, circumstances, predispositions and so on of each person.

Alternative interpretations

Some commentators think that Paul is referring to homosexual prostitution.  For Harper’s Bible Commentary, Paul is specifying

‘both the effeminate male prostitute and his partner who hires him to satisfy sexual needs. The two terms used here for homosexuality, which are absent from the list in Galatians, specify a special form of pederasty that was generally disapproved of in GrecoRoman and Jewish literature.’

But Schreiner objects that, if Paul was referring to pederasty here, he would ‘almost certainly’ have used the word paiderastēs.

Ian Paul adds:

‘Because pederasty was the most common form of same-sex activity, Greek had particular words for the two partners: erastes (‘lover’) for the older, ‘active’ partner; and eromenos (‘beloved’) for the younger, ‘passive’ partner. If Paul was speaking [only] against this form of activity, he would have used these words.’

As noted above, in the Authorised Version (KJV), the two terms are translated ‘effeminate’ and ‘abusers of themselves with mankind.’  Matthew Vines claims that this represents a centuries-long view that although the two terms clearly represented some kind of immoral behaviour, no connection was made with homosexual activity.  This link, states Vines, was not made until 1946, when, for the first time, an English translation was published that simply stated that

‘“homosexuals” will not inherit the kingdom of God.’

Vines is in error, however, for a brief survey of commentaries from the 18th and 19th centuries (including those of Poole, Barnes, and others) shows that they consistently understand the second of these terms as referring to the sin of ‘sodomy’ which, of course, is associated with male/male sexual activity.

Vines argues that ‘arsenokoites‘ probably refers to economic exploitation (likely through sexual means):

‘This may have involved forms of same-sex behavior, but coercive and exploitative forms. There is no contextual support for linking this term to loving, faithful relationships.’

But Vines, here as elsewhere, tends to ignore the Jewish foundations of Paul’s thinking.  A good case can be made for considering this word to have been coined (possibly by Paul himself) from two words that occur in the Levitical prohibitions of homosexual activity (in the LXX).