Therefore, prepare your minds for action,{Literally, "gird up the loins of your mind"} be sober and set your hope fully on the grace that will be brought to you at the revelation of Jesus Christ--
Girding up the loins of your mind ...  As he did frequently, Peter here gives a metaphorical meaning to well known expressions.  "Girding up the loins" meant tying up one's loose outward garments as a prerequisite to being able to work unencumbered.  It had the rough meaning of "Roll up your sleeves, and go to work."  Sure enough, the mind cannot roll up any sleeves; but the mind can be disciplined and prepared for the future by diligent prayer, study and contemplation.  It was of this that Peter spoke. From this, and many other instances in this letter, Peter's usual figurative method of expressing himself lends strong presumptive evidence to the conclusion that "Babylon" is a mystical name for "Rome."