One could be inclined to think that this phrase describes a third group in distinction from “the elders” (1 Peter 5:1) and “those who are younger” (1 Peter 5:5). Yet had that been Peter’s intent he would have used another formulation (e.g., “the rest of you”). Especially the use of the word “all” indicates that Peter directs this word to the entire body of his readers, that is, the “elect exiles of the Dispersion” (1 Peter 1:1), which is the entire congregation including the “elders” and “you who are younger.” All of them receive the instruction to “clothe yourselves with humility.”
5 Likewise, you who are younger, be subject to the elders. Clothe yourselves, all of you, with humility toward one another, for “God opposes the proud but gives grace to the humble.”