Do you not know may also be expressed as “Surely you know” (Good News Bible) or “I am certain that you know.”
Unrighteous is the word that Good News Bible translated as “heathen” in verse 1 (see the comments). However, the meaning has now broadened, so “wicked” (Good News Bible) is a more accurate translation.
Inherit means “take possession of,” as Israel took possession of the Promised Land as a gift from God (see Gen 15.7; Matt 5.5; 1 Peter 1.4). There is no thought here of “inheritance” from someone who has died. Good News Bible‘s translation “possess” reflects the meaning of the Greek more accurately than Revised Standard Version‘s rendering. The whole clause can be translated “… God will never give to the wicked the right to rule with him.”
Do not be deceived the Greek is different from 3.18 and means “Do not err,” “Make no mistake.” One could also say “You can be very sure of this.” The function of this clause is to draw attention to the list of vices that follows. We discussed several of these vices in the comments on 5.10-11. A difficulty in translating this list is that of finding different expressions, especially in common language, for terms having almost the same meaning. To translate the idea of being sexually immoral needs a more general expression than adulterers, which refers to the violation of the marriage bond. Another way to say this is “people who commit sexual sins.” Sexual perverts translates two Greek words that refer respectively to “the passive and active partners … in male homosexual relation” (Barrett). Translations generally combine these expressions, otherwise one would have to find technical expressions such as “catamites and sodomites” in English. Even “homosexual perverts” (Good News Bible) is rather difficult language; Revised English Bible has “sexual perverts.” Die Bibel im heutigen Deutsch has “relations with partners of their own sex”; Translator’s New Testament has “men who submit to or who practise homosexuality.” Many languages can use roundabout ways of speaking about homosexual relations. Paul thought of the practice of homosexuality as a form of perversion. If the people for whom this passage is translated do not normally share Paul’s attitude, it may be important to use a word meaning “pervert,” to make Paul’s meaning explicit.
The Greek word translated robbers is very close in meaning to thieves, but robbers refers to taking things violently.
Inherit the kingdom of God: see the last comment on verse 9a.
Quoted with permission from Ellingworth, Paul and Hatton, Howard A. A Handbook on Paul’s First Letter to the Corinthians, 2nd edition. (UBS Handbook Series). New York: UBS, 1985/1994. For this and other handbooks for translators see here .