Head of the body, the church: The Greek word kephalē (meaning “head”) often has the sense of authority over or chief when Paul uses it as a metaphor (see also 2:10, 19; 1 Corinthians 11:3–10; Ephesians 4:15; 5:23).
of the body: The metaphor of the church as Christ’s body shows the essential unity of Christ and the church (see also Colossians 1:24; 2:19; 3:15; Ephesians 1:23; 2:16; 4:4, 12; 5:23, 30).
firstborn from among the dead: See study note on Colossians 1:15.