Who have borne testimony to thy charity in the face of the Church. For of old the bishops and presbyters used to invite guests who came to give a sermon or exhortation in the church. And when they did this they would praise the charity and hospitality of Caius, of which they had experienced elsewhere. This duty of allowing hospitality to guests is spoken of by S. Clement (lib2Constit62), and is sanctioned by the4th Council of Carthage, cap4.
Whom if thou bring forward on their journey after a godly sort thou shall do well. (E. V.) To whom doing good thou shalt lead (deduces) worthily of God. The meaning Isaiah , To whom, if thou continuest to show kindness by receiving them to hospitality, thou wilt cause their journey to be easy, so that they will be able to reach the place whither they are going. This is a pious work and worthy of God. The word translated deduces in the Vulg. is Ï€Î¶Î¿Ï€ÎÎ¼ÏˆÎ±Ï‚ in the Greek. It does not mean that S. John wished Caius personally to accompany his guests, but it refers to his affording them provisions for their journey, and other things, such as guides and letters of introduction.
Worthily of God. As it is worthy of God that His worshippers should treat worthily other worshippers of Him, honouring them as ministers of God, and honouring God in them, by treating them charitably and reverently as befits servants and members of Christ. As Christ saith, Matthew 10:40, "He that receiveth you receiveth Me. He that receiveth Me receiveth Him that sent Me. He that receiveth a prophet in the name of a prophet shall receive a prophet"s reward."
Moraliter: let every believer examine himself, and see whether his works be full, perfect, and of such excellence as to be worthy of God; whether his charity be like to the charity of God and Christ; whether he live and act worthily of Christ. The gift which thou presentest to a king must not be of some mean sort. It should be excellent and regal. What then does it become us to offer unto God, who is King of kings and Lord of lords? This is what S. Paul admonishes the Ephesians (iv1.), "I, the prisoner of the Lord, beseech you that ye walk worthy of the vocation wherewith ye are called."