Ideally, friendships lead us into deeper communion with each other; those we love mirror the divine reality and so draw us closer to the One they reflect. In our humanness, however, we can forget that the friend is only a reflection of God and instead invest ultimate meaning in the relationship.
Agape is the love of God operating in the human heart. When we rise to love on the Agape level, we rise to the position of loving the person who does the evil deed, while hating the deed the person does.