Albert Barnes Commentary 1 Thessalonians 5:8

"But let us, since we are of the day, be sober, putting on the breastplate of faith and love; and for a helmet, the hope of salvation." — 1 Thessalonians 5:8 (ASV)

But let us who are of the day, be sober. Temperate, as is common in the daytime.

Putting on the breast-plate of faith and love. This is a favourite comparison of the apostle Paul. See it explained at length (see Barnes on Ephesians 6:14).

And for an helmet, the hope of salvation. See Barnes on Ephesians 6:17.