The Second Letter of Peter and the Letter of Jude both address false teaching – teaching that affects behaviour. The recipients had within their midst people whose lives contradicted the gospel that was preached. They defiled the love-feasts; they were themselves immoral and minimized the importance of law in the Christian life. They scoffed at the parousia and were fond of their own rhetoric. Michael Green offers a penetrating analysis that sets both letters in their historical context and shows their relevance to life today.