St. Gregory of Nazianzus wrote to Palladios in letter 103 (382 A.D.):
"If somebody asks me, "What is best in this life?" I shall answer, "Friends!" And among them, which ones are to be given preference? I would say: "Those who are good!" "And which ones shall you name first?" "I would not place anyone ahead of you in virtue, I am sure!" I do not write this to flatter Your Lordship but to honor your qualities which we proclaim, omitting nothing as far as it is in our power; we are not only your heralds, but also your fellow combatants, inasmuch as our prayers confer upon you a real power."
(translated by Georges Barrois, from The Fathers Speak, St. Vladimir's Seminary Press.
Gerbert of Aurillac wrote the following letter of friendship to Abbot Gerald of Aurillac, in 983, not long after Gerbert had arrived in Bobbio and then returned to France, unsure whether he would see his friends again (distant friends he had hoped he might be able to see as they passed through Bobbio each year on their way to and from Rome):
"I do not know whether the Divinity has granted anything better to mortals than friends, if only they are the ones who seem suitably sought out and suitably kept. Fortunate day, fortunate hour, in which we were permitted to know the man, the recollection of whose name has deflected all annoyances from us. Indeed, if I should enjoy his presence occasionally, not without cause would I think myself more blessed. In order to accomplish this I had established for myself a not unworthy abode in Italy.
But blind fortune, pressing down with its mists, enwraps the world, and I know not whether it will cast me down or direct me on, tending as I am now in this direction, now in that. But the features of my friend remain fixed in my heart. I mean him who is my lord and father -- Gerald -- whose counsel we will transform into deeds."
(translated by Harriet Lattin, in The Letters of Gerbert, Columbia University Press, 1959.