Eph 6:14

6:14 fastened . . . truth. The Roman soldier’s leather belt supported and protected his lower abdomen, gathered his tunic together, and held his sword. Paul seems to have in mind the confidence that comes from certainty about the truthfulness of God’s Word.

breastplate of righteousness. Believers are protected by the righteousness of Christ imputed to them (Rom. 4:6–11; Phil. 3:9), and they can stand up to the accusations of the devil; devil in Greek means “slanderer” (Rom. 8:31–34). Simultaneously, Paul sees believers taking on the righteous character of Christ (4:25; 5:9), while their growing conformity to His image gives them confidence in resisting temptation.