Armor Helmet

Why is the Christian armor, the helmet of salvation & the sword of the Spirit (spoken word of God) necessary?

Eph. 17 And take the helmet of salvation, and the sword of the Spirit, which is the Word of God: Praying always with all prayers and supplication in the Spirit, and watching thereunto with all perserverance and supplicaton for all saints;

Helmet of Salvation- Be saved, and believe that you are, and claim that you are when asked.
Sword of the Spirit (Bible): Quote scripture to defend yourself and God when asked questions from Satan and such, eg. How do you know Jesus is the right answer? Because He said, “I am the Way, the Truth, and the Life. No one comes to the Father except through me.”

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