Ephesians 4:23

And be renewed in the spirit of your mind. — The word translated “renewed” is not the same as the word “new” below. It is properly “to be made young again,” and the process of recovery is described as the natural effect of putting off the decrepitude of the old man, and the decay engendered by fleshly lusts. The effect is seen in “the spirit of the mind” — that is, “in the spiritual nature of the inner man.” The “spirit” of man is the mind or inner man, considered in its true relation as quickened and sustained by the Spirit of God. (See Romans 8, and especially Ephesians 4:16.) We note, in Colossians 2:18, the opposite condition of “the mind of the flesh,” in those who do not “hold the Head.” This spirit is spoken of as regaining its undying youth, as it were, naturally, when “the muddy vesture of decay” is cast off.