You see this theme emerge early in the letter in 1.13. Here's how the CSB renders the verse:
Therefore, with your minds ready for action, be sober-minded.
Most translations have something similar to the idea of "preparing your mind for action." The more literal NKJV makes the underlying idiomatic expression in the Greek more clear:
Therefore gird up the loins of your mind, be sober.As you likely know, given first-century dress, the long skirts of male clothing were pulled up and tied off prior to military action. "Girding up the loins" freed the legs for action, getting excess cloth out of the way so that you wouldn't trip over it. Obviously, since modern readers of the Bible don't do much "girding up the loins" anymore, the idiomatic expression doesn't communicate very well. Consequently, translations go with something like "preparing the mind" for action.
Regardless, the point is to prepare yourself for mental combat. This theme echos through 1 Peter:
"Be alert and sober-minded" (4.7)"Be sober-minded, be alert. Your adversary the devil is prowling around like a roaring lion, looking for anyone he can devour." (5.8)
Prepare your mind for military action. Be alert. Be sober-minded. Why? Because we are engaged in a spiritual battle.
This call to alertness parallels the call for watchfulness in the gospels. We must be watchful so that we won't be taken unawares by the coming of the kingdom.
In short, there is the steady drumbeat in the Scriptures calling us to mental preparedness, alertness, watchfulness, and vigilance. Our mental life is contested territory. Our thoughts are a battleground.
Given this, we prepare our minds for action.
