friendship :why it do not exists in this world.  and if exist is rare
friendship (real family from Allah CC ):
 friendly real does sacrifices to help the friend (true mother feeling/duty)
 friendly real protects the friend and the interests of the friend (true father feeling/duty)
 friendly real wants, tries, with the soul to be nearby, at all the moments
 (true brother feelings)

mean : 
>be together , HELPPER ; in bad or good moment. never leave. far or near are together, but do everything for to be together
>love with true love: (piety) : true friendship have piety , without interest in to take benefit from the other human. but want be together, by side, see the other grown, smile, be help always .
always working to Allah CC
then it is rare.
but,
in this world, Persons help others for:
 to obtain something in exchange (Interest...anything) = %98 of the humanity

of course , i can be wrong. Only Allah CC knows the true.