What does it mean to love one's neighbor?

To love one's neighbor means, while remaining within the earthly distinctions alloted to one, essentially to will to exist equally for every human being without exception...

Consider for a moment the world which lies before you in all its variegated multiplicity; it is like looking at a play, only the plot is vastly more complicated. Every individual in this innumerable throng is by his differences a particular something; he exhibits a definiteness but essentially he is something other than this - but this we do not get to see here in life. Here we see only what role the individual plays and how he does it. It is like a play. But when the curtain falls, the one who played the king, and the one who played the beggar, and all the others - they are all quite alike, all one and the same: actors. And when in death the curtain falls on the stage of actuality (for it is a confused use of language if one speaks about the curtain being rolled up on the stage of the eternal at the time of death, because the eternal is no stage - it is truth), then they also are all one; they are human beings. All are that which they essentially were, something we did not see because of the difference we see; they are human beings. The stage of art is like an enchanted world. But just suppose that some evening a common absent-mindedness confused all the actors so they thought they really were what they were representing. Would this not be, in contrast to the enchantment of art, what one might call the enchantment of an evil spirit, a bewitchment? And likewise suppose that in the enchantment of actuality (for we are, indeed, all enchanted, each one betwitched by his own distinctions) our fundamental ideas became confused so that we thought ourselves essentially to be the roles we play. Alas, but is this not the case? It seems to be forgotten that the distinctions of earthly existence are only like an actor's costume or like a travelling cloak and that every individual should watchfully and carefully keep the fastening cords of this outer garment loosely tied, never in obstinate knots, so that in the moment of transformation the garment can easily be cast off, and yet we all have enough knowledge of art to be offended if an actor, when he is supposed to cast off his disguise in the moment of transformation, runs out on the stage before getting the cords loose. But, alas, in actual life one laces the outer garment of distinction so tightly that it completely conceals the external character of this garment of distinction, and the inner glory of equality never, or very rarely, shines through, something it should do and ought to do constantly.