The term ‘peace’ in both Old and New Testaments came to denote well-being in the widest sense, including salvation, the source and giver of which is God alone. Peace was used for harmony among people (Acts 7:26; Gal. 5:22; Eph. 4:3; Jas. 3:18) and especially for the messianic salvation (Luke 1:79; 2:14; 19:42). The term could describe the content and goal of all Christian preaching, the message itself being called the gospel of peace (Eph. 6:15; cf. Acts 10:36; Eph. 2:17). The biblical concept of peace has to do with wholeness, particularly with reference to personal relationships. Peace describes an order established by the God of peace (1 Cor. 14:33; cf. Rom. 15:33; 16:20; Phil. 4:9). Christ himself is the mediator of that peace (Rom. 5:1; Col. 1:20). He gives peace to believers (2 Thess. 3:16); indeed, he himself is that peace.
Paul seems, therefore, to be making the following points: Christ is the vital cornerstone on whom the building is constructed. The foundation and position of all the other stones in the superstructure were determined by him. He is ‘the one from which the rest of the foundation is built outwards along the line of the proposed walls’. Accordingly, the temple is built out and up from the revelation given in Christ, with the apostles and prophets elaborating and explaining the mystery, which had been made known to them by the Holy Spirit (3:4–11, esp. v. 5)