"Do you, my child, love every one with the pure love of charity, but have no friendship save with those whose intercourse is good and true, and the purer the bond which unites you so much higher will your friendship be...
Do you form no other friendships. I say "form," because you have no right to cast aside or neglect the natural bonds which draw you to relations, connexions, benefactors or neighbours. My rules apply to those you deliberately choose to make."
also:
"There are some who will tell you that you should avoid all special affection or friendship, as likely to engross the heart, distract the mind, excite jealousy, and what not. But they are confusing things. They have read in the works of saintly and devout writers that individual friendships and special intimacies are a great hindrance in the religious life, and therefore they suppose it to be the same with all the world, which is not at all the case. Whereas in a well-regulated community every one's aim is true devotion, there is no need for individual intercourse, which might exceed due limits;--in the world those who aim at a devout life require to be united one with another by a holy friendship, which excites, stimulates and encourages them in well-doing. "
(Introduction to the Devout Life, Part III, Chapter 19 Real Friendship)