The armor of God is described in Ephesians 6:10-18. In this passage we are told that our primary battles are of a spiritual nature and that we need spiritual armor to be able to stand firm in the midst of these battles. The armor includes the following pieces:
Belt of truth: The belt of truth is the first item in our arsenal. A belt holds the other pieces of clothing and armor together. It secures the outfit and allows a soldier to move freely. Truth both secures us and gives us freedom (John 8:32). One of Satan's greatest offensive tactics is to deceive us; he is the "father of lies" (John 8:44). With the belt of truth around our waists, we are prepared to defend against this. This truth also applies to the way we live our lives. When we live with honesty and integrity, the other pieces of our armor – what could be considered our spiritual selves – stay intact. A life of integrity is not easily torn asunder.
Breastplate of righteousness: The breastplate of righteousness covers our hearts and other vital organs. In a sense, the breastplate covers the most vulnerable areas of a warrior. Proverbs 4:23 says, "Keep your heart with all vigilance, for from it flow the springs of life." The righteousness that guards a believer's heart is the righteousness of Christ (2 Corinthians 5:21).
Footwear of the readiness of the gospel: Our feet are to be "fitted with the readiness that comes from the gospel of peace" (Ephesians 6:15 NIV). Because we know the good news of Christ and by that knowledge experience peace in Him (John 14:27), our feet are willing to move. In obedience to Christ, we will flee temptations (1 Corinthians 10:14; 1 Timothy 6:11; 2 Timothy 2:22) and walk into whatever He has called us to (Psalm 86:11; Isaiah 30:21; John 15:10).
Shield of faith: The shield of faith is used to "extinguish all the flaming darts of the evil one" (Ephesians 6:16). When Satan attacks us, our faith in Christ lessens the blow. We are able to withstand the attack because we know whom we have believed (2 Timothy 1:12).
Helmet of salvation: A helmet protects the brain, basically our minds. It is because of salvation that our minds can be sound. We are assured of our eternities, and made righteous recipients of peace, practitioners of faith, and knowers of truth. Our minds are protected because of Jesus' work on the cross; we have been given the mind of Christ (1 Corinthians 2:12-16). A helmet can also serve as a signifier. When the enemy looks at us, he sees that we belong to Christ. We carry with us the seal of the Holy Spirit (Ephesians 1:13-14).
Sword of the Spirit: The sword of the Spirit is the Word of God. This includes God's written Word (the Bible), God's incarnate Word (Jesus as Logos), and God's spoken Word (the Holy Spirit within us). The sword is the one offensive weapon in the list. We are told, "For the word of God is living and active, sharper than any two-edged sword, piercing to the division of soul and of spirit, of joints and of marrow, and discerning the thoughts and intentions of the heart" (Hebrews 4:12). Second Timothy 3:16 (NIV) speaks of Scripture as being "God-breathed." When God spoke creation came into existence. He breathed life into man. There is power in the Word of God; this is why it is our best offense.
credit: What is the full armor of God?