1 Thessalonians 5:8

ἐνδυσάμενοι θώρακα κ. τ. λ., the thought of 1 Thessalonians 2:12-13; the mutual love of Christians, which forms the practical expression of their faith in God, is their true fitness and equipment for the second advent. Faith and love are a unity; where the one goes the other follows. They are also not merely their own coat of mail, requiring no extraneous protection, but the sole protection of life against indolence, indifference and indulgence. They need simply to be used. If they are not used, they are lost, and with them the Christian himself. The transition to the military metaphor is mediated (as in Romans 13:12-13) by the idea of the sentry's typical vigilance.