“... The Elder knows that whereas it is important not to entertain traveling teachers who are both deceptive and divisive (2 John 7-11), simply refusing hospitality to all teachers without first testing them is not an option. This is perhaps why the Elder never recommends this much simpler course of action in 2 John. Instead, he urges that the ‘elect lady’ measure visiting teachers by the standard of the traditional ‘teaching about Christ’ (2 John 9-10). Similarly, the Didache could easily have advocated keeping away those who ‘carry on a cheap trade in the teachings of Christ’ by refusing to show hospitality to any visiting teachers. Instead, it recommends examining visitors to see whether their teachings are right or wrong (Didache 12.1). The virtue of showing hospitality to strangers was widely and highly valued in early Christianity, and church leaders in particular were expected to be hospitable ...”