who understands what is the difference between temporal things and eternal, small and great, men and God. For he understands what is the eternal hope in presence of the true and good God. But who is he that loves God, save him who knows His wisdom? And how can any one obtain knowledge of God's wisdom, unless he be constant in hearing His word? Whence it comes, that he conceives a love for Him, and venerates Him with worthy honour, pouring out hymns and prayers to Him, and most pleasantly resting in these, accounteth it his greatest damage if at any time he speak or do aught else even for a moment of time; because, in reality, the soul which is filled with the love of God can neither look upon anything except what pertains to God, nor, by reason of love of Him, can be satisfied with meditating upon those things which it knows to be pleasing to Him. But those who have not conceived affection for Him, nor bear His love lighted up in their mind, are as it were placed in darkness and cannot see light; and therefore, even before they begin to learn anything of God, they immediately faint as though worn out by labour; and filled with weariness, they are straightway hurried by their own peculiar habits to those words with which they are pleased. For it is wearisome and annoying to such persons to hear anything about God; and that for the reason I have stated, because their mind has received no sweetness of divine love."
 Matthew 13:46.