Our Sages teach us that "All those who mourn for Jerusalem have the merit to witness her joy" (Tractate Ta'anis).

At first, this may seem to be irrational.  Why should weeping and mourning be the path to rejoicing?

In order to understand, we must first of all pay close attention to the wording of our Sages dictum.  They did not state that those who share in Jerusalem's mourning will eventually share in her joy; the statement was made in the present tense: "All those who mourn for Jerusalem have the merit to witness her joy" – here and now.

The individual who feels the city's distress and loss, also shares her joy – right now, in the present.  Their words imply that the city's destruction is at one and the same time her source of joy.

This is quite different from stating that, as a reward for mourning the destruction of the Sanctuary long ago, a person will eventually be given reason to rejoice.  In such a case, there is no intrinsic connection between the act of mourning, the destruction, and the source of happiness and delight.  We were not instructed to observe the three weeks of mourning in order to win a reward at some future time when prizes will be awarded. 

Rather, the reason of our mourning for Jerusalem is in order to afford us a period of time during which we review our actions, evaluate ourselves and our deeds, and seek ways to amend whatever needs improvement.  Self-improvement is in itself a reason to rejoice, because it circumvents the need for punitive measures in the future.  Once we learn the lessons of the first two destructions, and rectify our errors, we are assured that there will be no need of a third destruction, Heaven forbid.  This is certainly a source of contentment.

This insight is inferred also from the lamentations composed by the prophet Jeremiah.  In addition to his description of the destruction, the suffering, and the exile, he also tells us how we should react to the traumatic events taking place around him.  "Let us examine our ways, and let us investigate, and let us return to G-d" (Lamentations 3:40).

By reflecting on our misdeeds and our shortcomings, we can achieve the goal of "let us return to G-d."

G-d promised our forefathers that He would never abandon the Jewish people.  If we find ourselves distanced from G-d, it is not because He has moved away from us, but because we have removed ourselves from Him.  It follows that by improving our character and our deeds, we can return to Him, and to our former status, as Jeremiah implores: "Renew our days as of old!"

The only barrier which separates man from his Creator, the only obstacle to his returning to Him, is man himself.  If man persists in his misdeeds, he will continue to be distant from G-d.  On the other hand, if he chooses to rectify his deeds, he will find himself nearer to G-d as a result.  G-d does not move away from us; it is we who step back and separate ourselves from G-d. 

An individual who mourns over the destruction of the Temple and Jerusalem will consider the factors that brought about the fall of the city.  In this way, he succeeds in correcting some of those faults that brought the city to such dire straights nearly two thousand years ago.  This is a true reason to rejoice.  Jerusalem will be complete, and replete with joy, when she achieves her destiny as the site on this earth where Heaven and earth meet, where man can best bond with his Maker and experience His Presence.

In the words of the psalmist, Jerusalem is described as the city "that is united together" (Psalms 122:3).  It is in Jerusalem that Heaven and earth, the spiritual and the physical, meet.  It is here that we can best sense the closeness of our people to G-d. 

When our Father Jacob was fleeing from Esau, he spent one night on the mount which would eventually become the site of the holy Temple.  In his vision that night, he was shown a ladder which was firmly planted on the ground.  However, the top of the ladder reached up to the Heavens:

And he dreamed, and behold!  A ladder set up on the earth, and the top of it reached to heaven; and behold the angels of God ascending and descending on it.

(Genesis 28:12)

Here, on the site that would become Jerusalem, Jacob was shown the spiritual raison d'être of the future city: to join Heaven and earth, to provide the means for man to climb upward, rung after rung, toward higher, more spiritual spheres.

When we mourn for Jerusalem, we express our feelings of remorse over the fact that we no longer have this resource available to us.  Once, we had a "ladder" - a means of ascending to a higher standard of living in a spiritual sense.  The rungs of the ladder were there waiting for us to climb upward and enhance ourselves and our nation.  How much easier it was then to come closer to G-d!

Today, our bond with our Creator is far weaker.  By expressing our feeling of loss, by mourning the loss of the ladder – the Sanctuary – which was once ours and is no more – we strengthen our bond with G-d.  In this way, Jerusalem's purpose as a city finds fulfillment, no longer through the songs of the Levites and the offerings on the Temple Mount, but in the tears we shed over the distance which now separates us from our Father in Heaven.

Each tear is in itself an offering to G-d, a plea to once again draw closer to Him; as such, it brings us that much closer to the final, ultimate redemption for all.