At Caesarea, a mainly Gentile city, residence of the Roman proconsul (from A.D. 6 onward), lived Cornelius, a Roman centurion. He was in command of sixty to one hundred men and was the equivalent of an army captain or company commander. His unit was part of the Italian Regiment (the Cohores II Miliaria Italica Civium Romanorum). A cohort had ten centuries and was the equivalent of a modern military battalion. This battalion was an auxiliary unit, not part of a regular Roman legion. Such a battalion of archers was first made up of Roman soldiers and then filled out in the provinces.

Cornelius would have been a winsome figure for Luke's Roman audience. Polybius said of centurions, the backbone of the Roman army, "They wish centurions not so much to be venturesome and daredevil as natural leaders, of a steady and sedate spirit. They do not desire them so much to be men who will initiate attacks and open the battle, but men who will hold their ground when worsted and hard pressed and be ready to die at their posts" (Histories 6.24.9).

This "solid citizen" along with all his family (literally "all his household," which would have included household servants and military orderlies and their families) was devout and God-fearing. Luke does not quite use "God-fearer" (hos phoboumenos or hos seboumenos) as a technical term (Acts 10:2, 22, 35; 13:16, 26, 43, 50; 16:14; 17:4, 17; 18:7). But it does point to that class of monotheistic Gentiles who worshiped the God of the Old Testament, kept the Old Testament ethical code, attended synagogue, observed the sabbath and practiced the main requirements of Jewish piety (Levinskaya 1990). Because they refused to become proselytes, Jews still regarded them as ritually unclean Gentiles. Luke emphasizes Cornelius's piety: regular prayer (the Jewish practice was three times a day: m. Berakot 4:1; compare Dan 6:10) and many acts of charity among the needy of the Jewish people (Tobit 1:16; Sirach 7:10; 16:14; compare Mt 6:1-14).

God may do preparatory work in a culture before missionaries arrive. But note Cornelius's worship is directed to the one true God.