John identified himself and greeted the recipient of this shortest New Testament epistle to set the tone for what follows.
v. 1 As in 2 John, the Apostle identified himself as "the elder."We do not know exactly who Gaius was. Early church tradition did not identify him with Paul's native Macedonian companion (Acts 19:29), Paul's companion from Derbe (Acts 20:4), or the Corinthian Paul baptized who hosted the church in Corinth (Rom. 16:23; 1 Cor. 1:14).
"It is generally agreed that the Gaius to whom the Elder wrote this letter is not to be identified with any of the men by that name who were associated with Paul."3
The reason for this is that Gaius was a common name in Greek and Latin then, as the name John is in English now.4This Gaius probably lived somewhere in the province of Asia. He was obviously someone whom John loved as a brother Christian.
John's concern for both love and truth is evident again in this epistle (cf. 2 John). "In truth"means truly and in accord with God's truth. Both John and Gaius held the truth as the apostles taught it.
v. 2 Gaius was in good spiritual condition; he was walking in the light. John prayed that all would go well with him (NIV) and that he might enjoy as good physical health as he did spiritual health.
"He must surely have learned this from Jesus whose concern for people's physical troubles is attested in all four Gospels."5
The physical and general welfare of others should be of concern to us as well as their spiritual vitality. Usually Christians give more attention to the former than the latter, however, as our prayers often reveal.
v. 3 John had heard from others that Gaius was a man of the truth. That is, his lifestyle was consistent with the truth.
v. 4 We do not know if Gaius was John's child physically, spiritually (his convert), or metaphorically. The last usage of this word is the most common one in the New Testament. In this case he could have been a disciple of John or simply a younger believer (cf. 2 John 4; 1 Tim. 1:2).
