3 John (c.95–100 CE) is a brief personal letter praising Gaius for his hospitality to traveling Christian teachers, and warning against Diotrephes, a church leader who refuses to show support. It underscores the importance of welcoming missionaries and maintaining fellowship.

Author: Traditionally John the Apostle (the 'elder').

Date Written: Circa 95–100 CE.

Context: Set in the Johannine community, it addresses a practical issue of church conduct, highlighting the value of mutual support among believers.