The next section (chapters 5–6) deals with “three sins” the Corinthians:
1. Having relationship with “his father’s wife” (5:1–13);
2. Having court cases against each other in Gentiles courts (6:1–11);
3. Prostitution (6:12–20).
Verses 5:1–2. How such a situation could have a place in a Christian community remains a mystery (Lev 18:8; 20:11).
Verse 5:3–5. Paul’s judgement should be followed by the community: excommunication (see also 2 Thess 3:12–15). The purpose of such harsh judgement is the reformation of the sinner. The question is: who was that person? One among those few noble an influential brothers? In that case, the excommunication would be also a humiliation for that person. Unfortunately, he had have strong backing within the community, so to enforce Paul’s excommunication would not be easy.
Verse 5:6. A popular saying (see Matt 13:33; 16:6). Seeing from a positive side, the Christians should influence the world positively. But, here the Christians are being influenced negatively by one of their own (Gal 5:9).
Verses 5:7–8. Paul draws from the Jewish tradition of celebrating Passover (Ex 12:15.19). Before celebrating Passover, every Jewish family should remove from the house old yeast - “leaven”.
Now, we have an example in typology: Passover is connected with the sacrifice of Jesus on the Cross; The old leaven with sinful living, and the unleavened bread that was allowed to be eaten during the Passover is compared to a holy living - sincerity and truth.
Verses 5:9–13.
Verse 5:9 states that Paul wrote previous letter in which he already mentioned the problem of brothers who were fornicators. This verse combined with 5:11 paints a surprising picture of a community. Here Paul mentions brothers who are: (1) fornicators, (2) covetous - greedy; (3) idolaters; (4）railer - someone who uses abusive and insolent language; (5) drunkard; (6) - extortioner - forcefully demanding more payment - bribe.
This verse gives us a glimpse into the society of Paul’s time and particularly into the moral fabric of Corinth. Now, the converts were coming from such settings. To shake off such vices and live a new life in Christ was definitely not easy. Yes, that what Paul demanded from them; that what they were called in Christ to do (see Eph 2:2–3; Col 3:6).
Excommunication was a mean to ‘reinforce’ the awareness that they are called to a different way of life that the world around them. It has three aspects: