John’s second and third epistles address two sides of the issue of Christian hospitality. Early Christian teachers who traveled the Roman empire to spread the word of God often relied on fellow Christians for food and lodging.
2 John addresses the false teachers who took advantage of this hospitality. John urges the use of discretion when taking in anyone claiming to be a Christian and not to take them in if they are not spreading the truth; to do so would be to share in their deception.
3 John, however, says we should not turn away our true Christian brothers. This letter was written to a man named Gaius and praised him for the way he welcomed Christians into his home. In contrast, John describes a church leader named Diotrephes who refused to welcome traveling Christians and even excommunicated anyone who would be so welcoming. Diotrephes’s lack of hospitality is paralleled with that of the pagans. John tells Gaius that we ought to imitate what is good, not what is evil, that we may work together for the truth.