to hold separate parts together, so that what was apart works as one whole
The word is built out of "together" and a verb meaning "cause to step," so its root picture is making things step together. This meaning stays closest to that picture: parts are brought into contact and held there.
Paul uses it twice of the church as a body. What holds a body together is not the parts themselves but the joints and ligaments that fasten them, and Greek medical writers used this very verb for setting a limb into place. In Colossians the fastening goes with the supply that comes down from the head; in Ephesians it stands beside a word for being fitted together (συναρμολογέω) and the whole process happens in love.
The same verb then steps from bodies to people. When hearts are knit together in love, nothing physical is being joined, but the picture has not changed: what was separate now holds.
Nuances
Whether Ephesians 4:16 carries only the organic sense of a body held together at its joints, or also an echo of the instructional sense the verb has in the Greek Old Testament.
- majorityPurely organic: the body is held together through its joints and ligaments, exactly as in the near-twin sentence at Colossians 2:19.; E. Best, A Critical and Exegetical Commentary on Ephesians (ICC; T&T Clark, 1998), on Eph 4:16; A. T. Lincoln, Ephesians (WBC 42; Word, 1990), 264; F. Thielman, Ephesians (BECNT; Baker, 2010), ad loc.
- minorityThe instructional sense may also be heard behind the participle, since the immediately preceding verse is about truthful speech, so that the members grow together in truth.; H. W. Hoehner, Ephesians: An Exegetical Commentary (Baker, 2002), 564–65