2:4 living stone. As not just the foundation rock (I Corinthians 3:11), but also as a living stone that could bring life and sustenance, Christ is the fulfillment of the type suggested by the rock smitten in the wilderness, which thenceforth brought life-sustaining water to God’s people (see Exodus 17:6; Numbers 20:8; I Corinthians 10:4).

2:4 chosen of God. The Greek word here for “chosen” (also in I Peter 2:9) is the same as that for “elect” in I Peter 1:2 and 2:6. Thus, the “elect of God” are those “chosen by God.” Note also John 15:16 and Ephesians 1:4.

2:5 spiritual house. Believers are placed, as living stones quickened by Christ, into the spiritual temple of God (see Ephesians 2:19-22).

2:5 priesthood. Christ is High Priest (Hebrews 4:14), but we also are called on to exercise what has come to be called “the priesthood of the believer,” offering up spiritual sacrifices consisting of our own dedicated bodies (Romans 12:1), prayers of praise, thanksgiving and intercession (Hebrews 13:15), and material gifts for the full-time servants of God (Philippians 4:18).

2:5 spiritual sacrifices, acceptable to God. Since the one sacrifice of Christ has completely eliminated the need for repeated animal sacrifices, those sacrifices that are now “acceptable” to God include the presentation of our own bodies as a “living sacrifice” (Romans 12:1), the “sacrifice of praise” offered continually, doing good, and “communicating” (that is, sharing what we have with others), “for with such sacrifices God is well pleased” (Hebrews 13:15-16).

2:6 chief corner stone. Note that Peter here recognizes that Christ, not himself, is the foundation stone of the church (as some have misinterpreted the teaching of Matthew 16:18). He is quoting from Isaiah 28:16, showing that this Messianic prophecy was fulfilled in Christ. The Lord Jesus also called His words the true foundation (Matthew 7:24-27) and Paul confirmed that there is no other foundation (I Corinthians 3:11). Isaiah had also stressed that “in the LORD JEHOVAH is everlasting strength,” or “the Rock of ages” (Isaiah 26:4).

2:6 be confounded. “Make haste” in Isaiah 28:16 is interpreted by Peter as “be confounded,” meaning “be ashamed.”

2:7 head of the corner. The reference here is to Psalm 118:22, which in turn was referring to the tradition that, when Solomon’s temple was being built, the odd-shaped stone which seemed not to fit anywhere turned out to be the chief cornerstone, designed for the very apex of the temple. The stones had all been precisely cut deep in the quarry, so that no noise of construction could be heard while the temple was growing (see I Kings 5:17; 6:7). In analogous fashion, each believer is being laid quietly as a living stone in the great spiritual temple. But the unique stone of the pinnacle corner is Christ Himself, who is also the temple’s foundation. He is both underneath all, upholding us, and above all, crowning us as our glorious Head.