Cross reference
Romans 16:23
23 salute you doth Gaius, my host, and of the whole assembly; salute you doth Erastus, the steward of the city, and Quartus the brother,
Acts 19:22
22 and having sent to Macedonia two of those ministering to him -- Timotheus and Erastus -- he himself stayed a time in Asia.
1 Corinthians 1:14
14 I give thanks to God that no one of you did I baptize, except Crispus and Gaius --
2 Timothy 4:20
20 Erastus did remain in Corinth, and Trophimus I left in Miletus infirm;
3 John 1:1-6
1 The Elder to Gaius the beloved, whom I love in truth!
2 beloved, concerning all things I desire thee to prosper, and to be in health, even as thy soul doth prosper,
3 for I rejoiced exceedingly, brethren coming and testifying of the truth in thee, even as thou in truth dost walk;
4 greater than these things I have no joy, that I may hear of my children in truth walking.
5 Beloved, faithfully dost thou do whatever thou mayest work to the brethren and to the strangers,
6 who did testify of thy love before an assembly, whom thou wilt do well, having sent forward worthily of God,
Acts 19:29
29 and the whole city was filled with confusion, they rushed also with one accord into the theatre, having caught Gaius and Aristarchus, Macedonians, Paul's fellow-travellers.
Acts 20:4
4 And there were accompanying him unto Asia, Sopater of Berea, and of Thessalonians Aristarchus and Secundus, and Gaius of Derbe, and Timotheus, and of Asiatics Tychicus and Trophimus;