The Bible tells us that, But,
The Apostle Paul further states,
One of our main problems we must deal with is what the Bible calls the flesh, the old man, the old nature or whatever terms you choose to use. The flesh will not change, it must be exchanged for the Lord Jesus Christ (Galatians 2:20).

(See Ephesians 6:10‑18 — the armor of God). The second problem we have is,
The Apostle Paul alludes to the armor of God that the Divine Warrior, Jesus Christ, will be wearing when He returns to establish His eternal Kingdom (Isaiah 59:17‑18). It is this armor (as believers) that we are to put on in order that we may be able to stand firm against the schemes of the devil (Ephesians 6:10‑11).


Before a Roman soldier put on his armor, he put a belt around his waist. This held his garments together and served as a place on which to hang his armor. The belt of truth refers not to the facts of the gospel, but to a believer's integrity and faithfulness.


The breastplate of righteousness refers not to justification (Romans 3:24; 4:5), but to the outworked righteousness of Christ practiced in a believer's life (Romans 8:12‑13). As a soldier's breastplate protected his chest from an enemy's attacks, so sanctifying, righteous living (Romans 6:13; 14:17), guards a believer's heart against the assaults of the devil (James 4:7).


This verse does not speak of the spreading of the gospel, instead this refers to a believer's stability or surefootedness from the gospel which gives him peace so he can stand in the battle.


The shield in a Roman soldier's attire, made of wood, was about 2½' wide and 4' long. It was overlaid with linen and leather to absorb fiery arrows. Thus it also protected the other pieces of the armor; hence Paul used the phrase, "in addition to all this." The shield consists of faith. The idea then, is that a Christian's resolute faith in the Lord can stop and extinguish all the flaming arrows of the evil one (John 17:15).


The helmet and sword are the last two pieces a soldier takes up. A helmet, being hot and uncomfortable, would be put on by a soldier only when he faced impending danger. Having one's head guarded by a helmet gives a sense of safety, so the helmet of salvation refers either to present safety from the devil's attacks or to a future deliverance,
Finally, a Roman soldier would take in hand his sword, his only offensive weapon. "Of the Spirit" refers to the source or origin of the sword; hence it is "the sword given by the Spirit." "The sword of the Spirit" is specified as the Word of God. "Word" is the Greek word "rhema." It refers to an utterance of God occasioned by the Holy Spirit. See how Jesus used the Word three times when tempted by the devil (see Matthew 4:1‑11).


The manner in which a soldier takes up these last two pieces of armor is suggested by "praying" and "being alert." When the enemy attacks, and on all occasions, Christians are to pray continually in the Spirit (Jude 20; 1 Corinthians 14:14‑15) with all kinds of prayers. Their requests are to be for all the saints because of Satan's spiritual warfare against them.
Do you have on the armor of God? Are you waiting on Him to bring you His full salvation?

(Bibliography — The Bible Knowledge Commentary, page 644)