In the first chapter of Works of Love, Kierkegaard argues that love is something that must be believed in since it can not be seen. Because it can not be seen, people are deceived by love in 2 ways: 1) They think that there is love in someone when there is not or, 2) they are self-deceived and do not believe in love at all. Those who do not believe in love at all are by far the worst off since they have cheated themselves out of love, and deceived themselves for all eternity (since Christian love is eternal).
Kierkegaard distinguishes between two loves: (what he calls) Erotic love (self-love) and Christian Love (unconditional love). Since love is invisible and must be believed rather than seen, one must discern love by its fruits.
"By the fruits one recognizes the tree"
For Kierkegaard self-love is not necessarily bad, it is after all, still love. But it is a lesser love to that of Christian love. It blooms in season and then dies out again, and therefore it would be foolish to consider this love as comparable to Christian Love. Christian love is an unconditional love, an eternal love, the Love that every person should strive to achieve. But this love does not bloom, since everything that blooms must die. Christian love, however, "produces" an eternal fruit and therefore never blooms because it never dies.
Since love is hidden no one can get to the origin (in God) of love. Kierkegaard makes an analogy to the sun: Love, like the sun's rays, lights the path ahead of us so that we can see, but the foolish try to examine the origins of the rays, only to be blinded by the sun itself.
Kierkegaard later continues with a tree/fruit analogy: just as the tree is to be known by its fruits, the life of love is knowable by its fruits. However, for Kierkegaard, no expression (words or deeds) can prove or disprove anyones love, expression is not a fruit. The same words and deeds could be said/done by two different people and prove opposite results; conversely, opposite words could be said by two different people, still expressing love. Therefore, love must be known by its fruits.
He warns that we must be careful that we do not seek for the recognition of our fruits, but that we only seeks the fruits themselves. The hypocrite teaches that love is so hidden that the fruit is also hidden, or that the fruit (even poisonous fruit) proves nothing - for Kierkegaard, the Gospel teaches otherwise. However, he then throws a wrench into the works: You should not think that you will be able to recognize and rightly discern others fruit from the tree. No tree is set up to be the one that judges all other trees. There are only two judges able to properly discern the fruit one produces : One's self and God.
Kierkegaard continues on about the fear of God and the fear of self. It is these two attributes that will prevent one from being deceived by hypocrites. At the end of the chapter he comes around to the first point, "believe in love": only those who abide in love can recognize love.
Like is known only by like.
It's interesting that Kierkegaard promotes that there is fruit that comes from genuine love but in the next breath denies anybody (other than the self and God) the ability to judge by that fruit, which Kierkegaard clearly thinks is visible (unlike love).
This puts a lot of onus on the individual.
I'm a bit confused on how Christian Love - demonstrated by temporal beings - could possibly be eternal.
I'd also like to know if Kierkegaard thinks we even achieve Christian Love or is it only an (unreachable) goal that the Christian presses for?