Let's read on in Ephesians 6, verse 17a.
And you will need the helmet of salvation ... Most translations say: 'Take the helmet of salvation'.
👉A helmet offers protection against head injuries. So actually this is not a weapon, but none the less part of the armor. Kind of like a musician who cannot properly play without his sheet music. Although not an instrument, sheet music is essential for performance.
The helmet of salvation, how should we see it? The Bible speaks of being saved from eternal death that was the result of sin. But God's mercy is so abundant, and his love for us is so great, that while we were spiritually dead in our disobedience he brought us to life with Christ. It is by God's grace that you have been saved (Ephesians 2: 4-5).
God's love and grace exceed our shortcomings. He offers us eternal life in His presence if we are to believe in His Son Jesus Christ. Being 100% sure that He has rescued us from darkness and brought us into light protects us from every other thought ... Thoughts that we are not worth it, that we are lost, that it is not for us, that we did awful things ...
In that same chapter of the letter to the Ephesians, it says in verse 8: For it is by God's grace that you have been saved through faith. It is not the result of your own efforts, but God's gift, so that no one can boast about it.
Receive that gift and let it guide your thinking, it can save you a lot of headaches!