Friends are merely a part of human socialisation, it is an
interactive of human in term of having the same nature. U do not
need to be too emotionally involve. Those that can click with you
tends to be having a same ideologic and personnalities as you do,
but that does not mean that they will alway help and be with
you.
Some people due to their inward personalities, find no friend
around them and some rather befriend a dog or cat than their own
kind.
Family is different, it's a lifetime committment, a duty of human
kind to produce as all creature do, you cannot compare friends and
families. As a friend, you should alway bless or help your friend
and his/her family all the best.
There are many other relationship by which most of us have mistaken
it as friends which is actually not, such as classmates, colleagues
and teammates. Friend in one way or the other, is your private
matter. In losing or accepting a friend, you should be a judge of
yourself, but when the time comes, you hv to let them go as they
too have to let you go.