Cat. iii. § 3.  “Do not attend to the laver as mere water, but to the spiritual grace given along with the water”…“the mere water, receiving the invocation of the Holy Ghost, and of Christ, and of the Father, acquires a power of sanctity.  For since man is a two-fold being composed of soul and body, the cleansing element also is two-fold, the incorporeal for the incorporeal, the bodily for the body.  And the water cleanses the body, but the Spirit seals the soul, in order that having our hearts sprinkled by the Spirit, and our bodies washed with pure water, we may draw nigh to God.  When, therefore, you are about to go down into the water do not pay attention to the mere nature of the water, but expect salvation by the operation of the Holy Ghost.  For without both it is impossible for thee to be perfected.”