The entire teaching of the Armor of God is metaphorically speaking, and it is in the realm of fighting a spiritual enemy with spiritual armor.
Also, [although there are more places, but not enough time] in Ephesians 6:10-18 (NKJV) -"Finally, my brethren, be strong in the Lord and in the power of His might. Put on the whole armor of God, that you may be able to stand against the wiles of the devil (this is a spiritual, not physical enemy). For we do not wrestle against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this age,[a] against spiritual hosts of wickedness in the heavenly places. Therefore take up the whole armor (see verse 18below, as "prayer and supplication in the Spirit" is listed as one of the weapons) of God, that you may be able to withstand in the evil day, and having done all, to stand.
Stand therefore, having girded your waist with truth, having put on the breastplate of righteousness, and having shod your feet with the preparation of the gospel of peace; above all, taking the shield of faith with which you will be able to quench all the fiery darts of the wicked one. And take the helmet of salvation, and the sword of the Spirit, which is the word of God; [18] praying always with all prayer and supplication in the Spirit, being watchful to this end with all perseverance and supplication for all the saints—"
Yeshua - where are these things ever considered physical weapons? They are all spiritual, and they require spiritual faith and knowhow to use and utilize them in a manner and fashion to defeat a spiritual enemy.
With that said, how can you say, with a straight face, that PRAYER is not a spiritual weapon? It isn't a physical, tangible weapon that you can pick up and clobber the devil over the head with??? It is purely spiritual, and how we pray is the crux of the directive to, "praying always with all prayer and supplication in the Spirit!" What do you consider "in the Spirit" to mean?
How one prayers, once they enter their prayer closet, is between them and God. Especially if God hears our words, no matter what language we speak in, and moves upon those prayers! Would you say that God actually hears our words or rather what is on our heart and deep from within our spirit? If He doesn't know our deepest groanings than explain: Romans 8:26- (KJV) "Likewise the Spirit also helpeth our infirmities: for we know not what we should pray for as we ought: but the Spirit itself maketh intercession for us with groanings which" cannot be uttered.
And if our words are so important than why would Jesus have said, that, "Do not be like them, for your Father knows what you need before you ask Him." Matthew 6:8 (AMP)?
8