Ephesians 6:17

17 And take the helmet of salvation and the sword that the Spirit wields, which is the Word of God.

   

Salvation is a gift, our helmet is a gift. Salvation is placed upon us, we do not place it on ourselves. 

For it is by free grace (God's unmerited favor) that you are saved ( delivered from judgment and made partakers of Christ's salvation) through [your] faith. And this [salvation] is not of yourselves [of your own doing, it came not through your own striving], but it is the gift of God; Ephesians 2:8

And this is the will of Him Who sent Me, that I should not lose any of all that He has given Me, but that I should give new life and raise [them all] up at the last day. John 6:39

Finally, we are told to wield the Word of God as a sword. Jesus is the Word, He is our Head, He is our Vine, He is our Shepherd, and we are one with Him. Jesus is greater within us than anything that is in this world. Jesus causes us to walk in the paths of righteousness for His Name’s sake. We wield the Sword of the Word because we have been grafted into It, we are one with It, we cannot help but be who we have become.

So relax, our Father is the One Who dresses us for battle and He is the One Who always causes us to triumph in every battle. This is why we have confidence in our eternal salvation, because we can never lose it. 

For God’s gifts and His call are irrevocable. [He never withdraws them when once they are given, and He does not change His mind about those to whom He gives His grace or to whom He sends His call.] Romans 11:29

The Armor of God is placed on us by God. He sanctifies us completely in the power of His Truth. He will use us to wrestle evil and He will cause us to be victorious. He will show the world that they are loved, just as Jesus is loved, through us.