" that is a pure heart which is a single heart: and just as this light cannot be seen, except with pure eyes; so neither is God seen, unless that is pure by which He can be seen. "

― Augustine of Hippo , The Complete Works of Saint Augustine: The Confessions, On Grace and Free Will, The City of God, On Christian Doctrine, Expositions on the Book Of Psalms, ... (50 Books With Active Table of Contents)