On Love and Unity
I want you to know this, that Jesus Christ our Lord is Himself the true Mind of the Father. By Him all the fullness of every rational nature is made in the image of His image, and He Himself is the head of all creation, and of His body the Church (Col. 1:15-18). Therefore we are all members one of another, and the body of Christ, and the head cannot say to the feet, 'I have no need of you'; and if one member suffers, the whole body is moved and suffers with it (Eph. 4:25). But if a member is estranged from the body, and has no communication with the head, but is delighted by the passions of its own body, this means that its wound is incurable, and it has forgotten its beginning and its end. And therefore the Father of creatures, moved with compassion towards this our wound, which could not be healed by any of the creatures, but only by the goodness of the Father, sent forth to us His Only-begotten, who because of our bondage took upon Himself the form of a bondservant, and gave Himself up for our sins; for our iniquities humbled Him, and by His wound we are all healed; and He gathered us out of all regions, till He should make resurrection of our hearts from the earth, and teach us that we are all of one substance, and members one of another. Therefore we ought greatly to love one another. For he who loves his neighbor, loves God: and he who loves God, loves his own soul.
From the letters of St. Anthony the Great (+ 356)