Truthfulness

Wberefore take unto you the whole armour of God, that ye may be able to withstand in the evil day, and having done all, to stand. Ephesians 6:13

We must resolve, by God's grace, not to yield to satan. Resist him and he will flee. If we give back, he will get ground. If we distrust our cause, or our leader or our armour, we give him advantage. (Matthew Henry)

Stand therefore, having your loins girt about with truth, and having on the breastplate of righteousness. Ephesians 6:14

God desires truth, that is, sincerity in the inward parts. This is the strength of our loins; and it girds on all other pieces of our armour, and therefore is first mentioned. Righteousness must be our breast-plate. The breast-plate secures the vitals, shelters the heart. (Matthew Henry)

It's probably a good thing that people cannot see the "real" us--what's in our hearts. Our true motivation for the things that we do. I am always mindful of the fact that God does know the "real" me. This keeps me in my place--deflates my pride when I'm getting too puffed up. There is danger for the Christian if they lose sight of the fact that God knows their very hearts.