A Reading from St. Gregory, Pope and Doctor 

This is My Commandment:  That you love one another

Since all the Sacred Writings are filled with the commandments of the Lord, why does He say of Charity, as if it were some singular commandment: This is my commandment, that you love one another? if not for the reason that every commandment is a commandment solely of love, and that all of them are one single precept; because, whatever is commanded, is based solely on love. For as the many branches of a tree derive from one root, so the multitude of virtues derived from one charity.  And a branch of good work has no freshness, unless it remains rooted in charity.

The commandments of the Lord therefore, are many, and one:  many in the diversity of their works, one in their root of love.  And He teaches us how we are to hold fast to this love, Who, in many places of Holy Scripture, commands us to love our friends in Him, and our enemies because of Him.  For he truly possesses charity who loves his friends in God, and his enemy because of God.  For there are those who love their neighbors, but because of the bond of kinship or blood; and Sacred Scriptures do not forbid them this love. But one is the love to which nature spontaneously inclines us, and another the love to which we are obliged in obedience to the Lord’s commands.  The former truly love their neighbor; nevertheless they do not attain to the sublime rewards of love because the love they bestow is not spiritual but carnal.  So when our Lord said:  This is my commandment, that you love one another, He at once adds:  As I have loved you; as though He were to say simply:  Love one another as I have loved you.