Parepidemos (G3927) combines para (beside, alongside), epi (upon), and demos (people/land) — literally 'one who dwells alongside the people' but is not of them: a resident alien, a foreigner, a pilgrim passing through. Used three times in the NT: Abraham as a parepidemos in the cave purchase (Acts 7:6 alludes to it), Peter's greeting to 'those who are elect exiles [parepidemos] of the Dispersion' (1 Pet 1:1), and the exhortation to 'abstain from the passions of the flesh... as sojourners and exiles [parepidemoi]' (1 Pet 2:11).
The parepidemos identity is central to NT spirituality. Peter's entire first letter is addressed to believers as alien residents — not second-class citizens but people whose true citizenship (politeuma, Phil 3:20) is in heaven. Abraham 'went out, not knowing where he was going' (Heb 11:8) and 'lived in tents' because 'he was looking forward to the city that has foundations' (Heb 11:9-10). The parepidemos lives lightly — not clinging to temporary accommodations, not absorbed in the culture that surrounds him, not seduced by the world's priorities. His homesickness for the heavenly city makes him free and dangerous in the best sense: free from what this world offers, dangerous to the kingdom of darkness.