en_tn/1th/05/08.md

sons of the day

This is an expression for believers in christ. AT: "believers in Christ" or "people of the light". (See rc://en/ta/man/translate/figs-idiom)

let us be sober

"let us exercise self-control"

put on the breastplate of

As a soldier would put on a breastplate to protect his body, a believer who lives by faith and love will find protection. AT: "protect ourselves with" (See: rc://en/ta/man/translate/figs-metaphor)

for a helmet

As a helmet protects a soldier's head so does assurance of salvation protect the believer. AT: "and know" (See: rc://en/ta/man/translate/figs-metaphor)

but for the obtainment of salvation

"but to receive salvation"

whether we are awake or asleep

"whether we are alive or dead" (See: rc://en/ta/man/translate/figs-euphemism)

build each other up

"encourage each other"