Dear beloved: The fifth piece of armor that we put on is the helmet of salvation, Ephesians 6:17 says to take, or put on the helmet (gr. perikephalaia) of salvation. The battlefield for a person's soul and spirit takes place first in the mind, that is where the temptations and evil thoughts and desires originate and from there eventually become acted out in the flesh. So it stands to reason that if we can protect our minds from being taken over by demonic thoughts, we will have victory on the battlefield.
In Romans 12:2 Paul tells us, And be not conformed to this world: but be transformed by the renewing of your mind, that you may prove what is good, and acceptable, and perfect will of God.... God wants us to prove His perfect will in our life, and it starts by renewing our mind to conform to Him and to the image of His Son. Paul goes on to say in Romans 8:29, those that God foreknew(that would be each of us), He predestined to be conformed to the image of His Son, that he might be the firstborn among many brethren. Jesus admonished us to love Him with all our heart, all our soul, and all our mind (Matthew 22:37), so He knew the mind was at the point of the battle.
So how do we go about protecting our minds, or putting on the helmet? Paul tells in 2 Corinthians 10:3 For though we walk in the flesh, we do not war after the flesh; v4 for the weapons of our warfare are not carnal, but mighty through God for pulling down strongholds, v5 Casting down imaginations, and every high thing that exalts itself against the knowledge of God, bringing into captivity every thought to the obedience of Christ. There it is: pull down strongholds, cast down imaginations, and take every thought captive! Sounds kind of like a wrestling match, a battle royal!
Paul goes on to give Timothy some good instruction in 2 Timothy 2:15, Study to show thyself approved unto God, a workman who is not ashamed, rightly dividing the word of God. So we need to study God's word, line upon line, precept upon precept, a little here and a little there, until we
immediately know when Satan is trying to get into it with his lies and deceiving thoughts.
In closing, keep in your mind beloved that we have the mind of Christ. 1 Corinthians 2:16, Paul tells us, For who has known the mind of the Lord, that he may instruct Him? But we have the mind of Christ. If we have the mind of Christ, we should be thinking like him. Phillipians 4:8 Finally brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things. v9 Those things, which you have both learned, received, and heard, and seen in me, do; and the God of peace shall be with you. May God bless you and guard you this day, in Christ, Jim