It is the Spirit who gives life; the flesh is no help at all. The words that I have spoken to you are spirit and life. —John 6:63 ESV
Our Lord says, “It is the Spirit who gives life.” By this He means that it is the Holy Spirit who is the special author of spiritual life in man’s soul. By His agency it is first imparted, and afterwards sustained and kept up. If the Jews thought He meant that man could have spiritual life by bodily eating or drinking, they were greatly mistaken.
Our Lord says, “The flesh profits nothing.” By this He means that neither His flesh nor any other flesh, literally eaten, can do good to the soul. Spiritual benefit is not to be had through the mouth, but through the heart. The soul is not a material thing, and cannot therefore be nourished by material food.
Our Lord says, “the words that I speak unto you, they are spirit and they are life.” By this He signifies that His words and teachings, applied to the heart by the Holy Spirit, are the true means of producing spiritual influence and conveying spiritual life. By words thoughts are begotten and aroused. By words mind and conscience are stirred. And Christ’s words especially are spirit-stirring and life-giving.