By Etymology

Word History: A friend is a lover, literally. The relationship between Latin amīcus "friend" and amō "I love" is clear, as is the relationship between Greek philos "friend" and phileō "I love." In English, though, we have to go back a millennium before we see the verb related to friend. At that time, frēond, the Old English word for "friend," was simply the present participle of the verb frēon, "to love." The Germanic root behind this verb is *frī-, which meant "to like, love, be friendly to." Closely linked to these concepts is that of "peace," and in fact Germanic made a noun from this root, *frithu-, meaning exactly that. Ultimately descended from this noun are the personal names Frederick, "peaceful ruler," and Siegfried, "victory peace." The root also shows up in the name of the Germanic deity Frigg, the goddess of love, who lives on today in the word Friday, "day of Frigg," from an ancient translation of Latin Veneris diēs, "day of Venus."

Online Etymology Dictionary
O.E. freond, prp. of freogan "to love, to favor," from P.Gmc. *frijojanan "to love" (cf. O.N. frændi, O.Fris. friund, M.H.G. friunt, Ger. Freund, Goth. frijonds "friend," all alike from prp. forms). Related to O.E. freo "free." Meaning "A Quaker" (a member of the Society of Friends) is from 1679. Feond ("fiend," originally "enemy") and freond, often paired in O.E., both are masculine agent nouns derived from prp. of verbs, but are not directly related to one another.