This is the first and greatest commandment: Thou shalt lave the Lord thy God with thy whole heart; but the second is like unto it: Thou shalt love thy neighbor as thyself. -Mt 22:37-39
My God and my Lord! what need was there of commanding us to love Thee? Art Thou not most lovely in Thy infinite perfections? and for the infinite love Thou Dearest to us, dost Thou not deserve our love? How, then, is it possible that any one should not love Thee? If there is such a person, it must be because he has not deserved to know Thee. For, a soul that knows God, cannot help loving Him, and loving Him in proportion to his knowledge of Him; so that if he loves Him but little, it is a sign that he knows Him but little; and the more his knowledge increases, the more his love will go on growing. -St. Teresa
The blessed Jacopone was so much affected at seeing so many lose their souls by offences against God in the Carnival-time, that he went about crying, “Amor non amatur, amor non amatur, quia non cogmtur” — Love is not loved, Love is not loved, because it is not known.
St. Philip Neri, too, often exclaimed: “O Lord, I do not love Thee, because I do not know Thee.”
Text from A Year With the Saints (New York: P.J. Kenedy & Sons, 1891).