1 Corinthians 1:14
I thank God that I baptized none of you, but Crispus and Gaius;
Cross-reference
Acts 18:8
Historical context
Acts 18:8 records Crispus believing and being baptized, confirming Paul's mention of baptizing Crispus in 1 Corinthians 1:14.
Romans 16:23
Historical context
Romans 16:23 mentions Gaius as a host, the same Gaius Paul baptized in 1 Corinthians 1:14 — a direct link.