Mother- Father, Brother- Sister, Siblings all are decided by destiny. Life partner would be decided by family (except in love marriages), but friends are the only thing in life which we can select, which are selected by our choice not by destiny so take care of those friendships.
Friends are the beautiful creature by god who loves like a family and oppose you like enemy, this relationship has all the spices you can get in all your life from different people. Friendship is like planting a tree if it is taken care with all your heart then it will be fruitful to you for your whole life, if it is not taken care it could dry and die. So friends take care of all your friends who will always on your side in any situation.
Give your friendship sufficient time and emotions and keep it alive for your lifetime.