One must show one’s love to the friends because showing it evokes their hearts to love. Thus, each receives strength to act in love of friends, as the force of love of each friend is integrated in one’s friend, so each person will have the strength of the whole society.
If they do not show love for one another, the strength to love in each of them is deficient since it becomes very hard to justify one’s friend. Every person thinks that he is the righteous one, that he is the only one engaged in love of friends, because he still can’t feel his friends’ hearts. And this gives him only small powers to work in love of man. Hence, each must manifest his love to all the others, and thus everyone will have the strength to love.
Courtesy of http://www.youtube.com/watch?v=6Xvl5NIYRMo