en_tn/eph/04/03.md

to keep the unity of the Spirit in the bond of peace

Here Paul speaks of "peace" as if it were a bond that ties people together. This is a metaphor for being united with other people by living peacefully with them. Alternate translation: "to live peacefully with one another and remain united, as the Spirit made possible" (See: rc://en/ta/man/jit/figs-metaphor)