Okay, so I was wrong.
I've been rereading Ephesians 6, and the more I do, the more I see the emphasis the WORD of GOD puts upon our spiritual armor. That word picture wasn't just Paul's idea, but God's. Oops, sorry, Lord! I definitely don't want to get into trouble with You!
Nevertheless, I still believe that God wants us to take up all seven of the spiritual weapons mentioned, besides all the others like humility, the name of Jesus, the blood of Jesus, etc. (Please send me additions to that list, it would be fun to have a list of our arsenal.)
Last time I looked at truth as an indispensable weapon. The second one is righteousness. Most people automatically think of the imputed righteousness we have in Christ, and that's certainly the most important aspect. But I wonder how this really differs from weapon Nr. 5, salvation.
I want to suggest that there is another aspect to righteousness: living right. It means having a heart that is committed to obeying the Lord fully. If we are consciously disobeying and living in sin, we're vulnerable to the enemy, no matter how much we believe in Christ's death for us. All of us are still immature in many ways, and we fall short, but God looks at the sincerity of our hearts. Stumbling out of immaturity is a far cry from rebellion, though they may look the same on the outside. (Thank you, Mike Bickle, for that insight!) I believe the goal of the Holy Spirit working within us is to make us more and more righteous in our actual righteousness, though on this side of eternity it will never match Christ's perfect righteousness that has been imputed to us.
The third spiritual weapon is a tongue twister, especially for a non-native speaker like me. What on earth does "having your feet shod with the preparation of the gospel of peace" mean? At the risk of oversimplification I want to suggest that it is simply the declaration of the good news. When we share the gospel with someone, we are extending the kingdom of God and taking away territory from the enemy. No wonder most Christians never open their mouths to witness! It is a spiritual weapon the enemy fears greatly, and he does everything he can to shut it down. Sadly, I haven't overcome his intimidation in this area yet either.
The fourth weapon is faith. As a weapon I believe it can be used both defensively and offensively. Defensively, when we are remembering what the Lord has spoken to us personally through a rhema word at some time. Offensively, when we decide to "live by faith and not by sight" in a given situation, i. e. to trust the Lord and not our circumstances, simply on the basis of his word.
The fifth weapon is salvation - see above. I'd be grateful for any insights on the differences between salvation and righteousness.
The sixth weapon is the word of God, which Scripture calls the "sword of the Spirit." Jesus used it in the tempation in the wilderness in order to defeat Satan. How much more do we need to learn to use it!
The seventh weapon mentioned here is prayer in all its forms. It's prayer in the Spirit, not the flesh or our own imagination, that is effective and powerful. I'm not even going to begin to try to say more about it!
Now, go, take up your armor - and don't take it off when you go to bed, either!