Cornelius … fell at his feet to worship him: This act was probably more than just bowing to an important person of rank. The Bible says worship is for God alone (see 14:11–17; Exodus 20:3; Deuteronomy 5:7; Matthew 22:37–38; Mark 12:29–30; Luke 10:27; 1 Corinthians 10:14; Colossians 3:5; 1 Peter 4:3; 1 John 5:21; Revelation 4:10; 9:20; 22:8–9).
Peter was just a fellow human being whom Cornelius should not worship.