Wolfson, Philo, II, p. 373, suggests that these “Heaven Fearers” are probably to be identified with “resident aliens” (gere toshab) who observe Noachian laws or with “sympathizers.” He notes that Maimonides (Mish-neh Torah, Issure Biah 14.7, Melakhim 8.10–11) identifies the “pious of the nations” with “resident aliens.” Wilcox, “The ‘God-Fearers’ in Acts,” pp. 116–117, argues that the yirei shamayim in this passage are not “sympathizers” and that the passage is, rather, referring to two kinds of Jews, proselytes and Jews by birth; but, if so, we may respond that the fact that two types of proselytes are mentioned is an indication that the members of one type were not full proselytes.