Belos (βέλος) refers to a thrown or shot missile — an arrow, dart, or javelin. It appears only once in the New Testament, in Ephesians 6:16, as the "flaming arrows" (ta bele ta pepyrōmena) of the evil one which the shield of faith extinguishes. The word captures the swift, piercing nature of spiritual attack.
The armor of God passage (Ephesians 6:10–17) is one of Scripture's richest descriptions of spiritual warfare. The "flaming arrows" (bele) of the evil one represent the fiery temptations, doubts, accusations, and spiritual assaults that Satan launches against believers. The shield of faith (thyreos — a large body shield, not a small round shield) is specifically designed to quench these. Faith — trust in God's character, promises, and power — is the primary defensive weapon against every form of spiritual attack.