If the sins Paul lists in this passage are so detrimental to Christian community that those who commit them warrant exclusion from the Christian community it is incumbent on us to be clear what the terms mean – otherwise we could be in danger of excluding people for behaviours that might be less than exemplary but which do not constitute covenant disloyalty.

I would suggest that five of the terms do not pose great difficulty of interpretation, even if we are not always consistent in application.

• Greedy/Swindler: Someone who knowingly defrauds others.
• Idolaters: Someone who deliberately worships an idol. In British culture this is unlikely to be an issue in the way it might be in, say, a Hindu culture. Which is not to deny that idolatry is a problem in British culture but that it does not take the same overt form it would have in Corinth, or might do in Delhi.
• Slanderers: Someone who deliberately defames others. (In a social media age this is probably a sin we should be more alert to than we are.)
• Drunkards: Those who persistently and deliberately drink to the point of inebriation.

Which leaves us with the final (actually first!) term and the one that seemed to be the biggest issue for the Corinthians, just as it is for us: Sexually immoral. What do we do with that? How do we define sexual immorality?

The interpretation and extent of what is meant by porneia has been much debated in recent years, especially in relation to what Christ meant by this term in his instructions regarding divorce. However, it seems most straightforward to read it as any sexual activity outside the covenant bounds of legitimate marriage. Indeed, the close connection between the covenant of marriage and the covenant between God and his people should be clear: porneia disrupts them both. In 1 Cor 5-7 Paul spells out some details of what this looks like, dealing with issues specific to the Corinthian context, but the general point is clear: sexual immorality is any sexual activity outside the bounds of covenant marriage. We should expect non-believers to indulge such behaviour, but it should be unthinkable for those in covenant with Christ.

In terms of the extent of exclusion that should be extended to a ‘brother’ guilty of such sin we could proceed as suggested previously: that the believer who ‘makes a mistake’ and falls into sin should be warned and brought to repentance and forgiveness, but the brother who hard-heartedly persists in his sin must be expelled: with such a one do not even eat. This would reflect what we know of the incestuous man of 1 Cor 5 – that he was not guilty merely of a one-off aberration, but had settled in a persistent manner of living utterly at odds with the demands of the gospel.

If this is a fair interpretation of what Paul writes we can easily imagine some ‘for instance’s’:
• The 16-year-old boy who finds it hard to keep away from porn but knows what he is doing is wrong and wants to be free of it should not be excluded from the church but discipled to the point where he learns to walk free of porn.
• The lonely single woman who forms an unwise attachment with an unbelieving work colleague and ends up going to bed with him but confesses with sorrow what she has done should not be excluded from the church but helped to find her true comfort in Christ.
• The husband who repeatedly and deliberately neglects his wife and visits prostitutes and refuses to back down when confronted should be excluded from the church.
• The wife who initiates divorce from her husband without legitimate cause should be excluded from the church.

Such examples (and the many more we could think of) are always pastorally complex, and painful, but relatively simple to think through in that the sin and the solution are easy to see. The real sticking point in our context is where there is disagreement as to what constitutes sexual immorality, specifically, whether same-sex relationships are by definition immoral.

Does homosexuality always come within the definition of sexual immorality?
Once, not so long ago, this would have been a laughable question, but today it is a very serious one indeed as revisionist evangelicals argue that ‘faithful, monogamous, same-sex relationships’ are valid. As Matthew Vines expresses it in God and the Gay Christian, “God’s gift of sexual love in marriage should be affirmed. There is no biblical reason to exclude the covenantal bonds of gay Christians from that affirmation.”

This means our application of “with such a one do not even eat” will to a large extent be determined by the extent to which we consider homosexuality to represent sexual immorality.

If we are going to maintain a traditional, biblical, sexual ethic the inevitable consequence is that we will find ourselves at odds with those who proclaim themselves to be brothers – and are winsome and compelling to boot - but who espouse a sexual ethic very different from what the Church has always understood. In such a climate the pressure to accommodate ourselves to a more sympathetic handling of homosexuality is powerful, even if we do not fully espouse same-sex marriage. To be consistent in identifying homosexual practice as sexually immoral demands an equal consistency in applying 1 Cor 5:11: that persistent, intentional same-sex activity by those who claim to be brothers must result in exclusion, and that we should be very cautious as to how we engage with those who teach that such activity can be morally right. To put it mildly, taking this stance is likely to be increasingly uncomfortable.

Conclusion
The lordship of Christ is both liberating and demanding. As NT Wright observes regarding Romans 6, the gospel is radically inclusive but Christian holiness is radically exclusive: “The idea that Christian holiness is to be attained by every person simply doing what comes naturally would actually be funny were it not so prevalent.” If we are to be faithful to the demands of the gospel and lordship of Christ we may need to take rather more seriously texts like 1 Cor 5 (and Rom 6). The fact that so many of us struggle so much to do so perhaps illustrates that we don’t really believe sexual immorality to be that serious an issue; or that we are not really convinced that ‘faithful same-sex relationships’ represent sexual immorality. Perhaps we are far more Corinthian than we realise.

It seems to me that we stand on the cusp: either to flow with the cultural tide on issues of sexual morality or to hold the much more challenging line of not tolerating persistent sin within our churches. The latter course will be extremely uncomfortable at many points, and will lay us open to charges of bigotry and intolerance. These are charges that we will need to be ready to take.