A bosom friendship* contracted with a person without regard to his spiritual character is harmful after death.
A bosom friendship means one so intimate that it involves loving not only the friend's external man but also his internal man, and this without enquiry into what sort of a person he is inwardly or in spirit. This means without enquiring whether the affections of his mind derive from love towards the neighbour and love to God, and are thus capable of association with the angels of heaven; or whether they derive from love directed against the neighbour and love directed against God, so being capable of association with devils. Many people enter into such friendships for various reasons and for various purposes. This kind of friendship is to be distinguished from external friendship which is merely personal, and exists for the sake of various pleasures of the body and the senses, and for various kinds of contact. This personal sort of friendship can be contracted with anyone, even with the clown who plays the fool at a duke's table. This is simply called friendship, the other, bosom friendship; friendship is a link at the natural level, love a link at the spiritual level.
* The Latin phrase means literally 'a friendship of love'.