Peter has already identified his readers are “exiles” (1 Peter 1:1, 1 Peter 1:17), that is, displaced persons who don’t really fit in their communities. That leads to an identity crisis, a sense of worthlessness. In the entirety of this first section of his letter (1 Peter 1:3 – 2:10) Peter has laid before his readers God’s gracious and mighty work for them and in them so that they might know that they are not worthless. With these four glorious titles in the present verse, the apostle sums up what God has made of them and so reminds his readers of the grand vista one may see and enjoy post birth, an understanding of reality much more glorious than what was possible prebirth. Though their compatriots might disparage them as nothings, the Lord God honours them with an exalted identity in his world. This identity in turn outlines the purpose God’s elect have in God’s world.
9 But you are a chosen race, a royal priesthood, a holy nation, a people for his own possession, that you may proclaim the excellencies of him who called you out of darkness into his marvelous light.