The third epistle of John is a short letter written to a believer named Gaius, who welcomed missionaries into his home and lived out the teachings of the apostles. John encourages him in his faith, and warns of an overseer named Diotrephes, who didn’t acknowledge John’s authority and refused to welcome these godly teachers into the church. He emphasizes the importance of both love and discernment in order to avoid false teaching and division within the church.