In Scripture the term typically denotes Israel’s enemies (and hence God’s enemies), for example, Psalm 2:1, and so our default is to assume that they are outside the city (and so attracted to the city’s light as moths to a candle). The vision of the New Jerusalem, however, involves the new heaven and the new earth, with God dwelling with his people (Revelation 21:1–3) and God’s enemies (= “nations”) thrown into the lake of fire (Revelation 20:15). By that understanding, “the nations” are inside the city and would in fact be the elect (and regenerated) percentage from the nations whom God has saved. The argument against that understanding is the reference in Revelation 21:25 to the city’s gates being ever open so that kings “will bring into it the glory and the honor of the nations” (Revelation 21:26). That is clearly a reference to nations still outside the city—attracted by its light. We need to wait till Revelation 21:26 to discover the answer.
24 By its light will the nations walk, and the kings of the earth will bring their glory into it,