Commentators widely agree this verse prophesies the New Testament reality of the 'priesthood of all believers' (1 Peter 2:9). In the Old Covenant, priesthood was limited to the tribe of Levi, but Isaiah foretells a time when all of God's people would be called His priests and ministers. John Calvin notes this priesthood is fulfilled in Christ, where every believer is consecrated to offer spiritual sacrifices, such as their own lives in service to God (Romans 12:1).