Three Interpretations
What will change in the Messianic Age? In addition to the obvious changes, such as G‑d’s revealed presence, universal peace, the rebuilding of the Bais Hamikdash, etc., there are some startling predictions about changes to the world of nature that are alluded to in the beginning of this week’s parsha:
“If you will go in the way of My statutes and guard My commandments and you will observe them; then I will give you your rains in their season, and the land shall yield her produce, and the trees of the field shall yield their fruit.”
There is an apparent redundancy in this verse. The words, “…the land shall yield her produce” refers to everything that comes from the land including trees and their fruits. Why the need for the additional words “and the trees of the field shall produce their fruit?”
Rashi anticipated this question and states that it refers to non-fruit-bearing trees, which will bear fruit in the future [Messianic Age].
The Halachic Midrash (Toras Kohanim) provides two other interpretations concerning the uniqueness of the fruits of the trees in the future Messianic Age:
In that Age the trees will yield their fruit on the same day they are planted. Furthermore, the Midrash states, in the Messianic Age the trees themselves will taste like their fruits.
In short, there are three incredible predictions concerning the trees and their fruits:
(a) Even non-fruit-bearing trees will produce fruit.
(b) Trees will bear their fruit on the same day they are planted.
(c) The wood of the trees will taste the same as their fruits.
Three Questions
Several questions come to mind:
First, what significance is there to these miraculous changes? We know that G‑d does not perform miracles needlessly. A miracle is intended to save people from a calamity, demonstrate G‑d’s power to non-believers (such as in the Ten Plagues in Egypt) or to introduce a new parallel spiritual energy. What purpose is served by having non-fruit-bearing trees taste like the fruits which they will bear on the same day they are planted? 
Second, what is the connection between these three miracles and the Messianic Age?
Third, what relevance do these future miracles have to our lives now? The Tanya teaches us that all those things that will happen in the future are determined and generated by our commensurate actions today. How can we apply these supernatural changes to our lives in the present?
Three Obstacles: Sub-text, Context and Text
To understand these three miracles, we must start by analyzing some of the primary obstacles to spiritual growth in exile that will disappear in the future. Upon reflection, we may discern three factors or patterns for which the “tree/fruit miracles” will furnish profound metaphors.
First, in the present time we can only see the surface of whatever it is that our eyes—physical or intellectual—see or perceive. No matter how deeply we probe life’s mysteries, we can only scratch the outer layers. We cannot see beyond the surface to the sub-texts of the world around us, events, personalities or even our own soul’s potential.
Second, even what we are able to see on the surface is limited in scope.  When we see an event, we don’t necessarily know what preceded it or what will follow. Thus, our analysis of what we see is, by definition, incomplete and often skewed. The classic example is a blindfolded person brought into an operating room. When the blindfold is removed, he “sees” masked men standing ready to cut an unfortunate hostage tied to a table. Without a proper context, our view is significantly distorted.
Finally, even if we are able to know both sub-text and context, we might still be hindered by our inability to see a consistency that underlies all things. On the macro level, we see many troubling contradictions. For example, when the good suffer and the evil prosper. On a personal level, our positive actions often stand in stark contrast to our true inner negative feelings. The good that we do can be superficial and inconsistent. One day we will be inspired; the next day, we may be down in the dumps. This, in turn, breeds feelings of “why bother to do what is right; it won’t last; it’s insincere and nothing really makes sense.” Indeed, we may consider the entire text and narrative of our lives as either boring or a total mess.
Three Remedies  
The Torah compares a human being to a fruit-bearing tree.  Our fruits are the good deeds that we perform.  The tree which does not bear fruit obviously refers to the person who lacks good deeds.
The first miracle to occur will be that everybody will “bear fruit.” No person will be able to suppress the innate desire to abide by G‑d’s will and do good for others. In truth, there is no such thing as a Jew without a Mitzvah. Our Sages declare, “even the sinners of Israel are filled with Mitzvos as a pomegranate is filled with seeds.”  However, the negative energies that exist on the surface can stifle and obscure people’s innate righteousness and cause their good deeds to go unnoticed. All that one can see in these pitiful individuals during our Exile is their negative exterior. In the Messianic Age, that façade will be stripped away and our good deeds and innate holiness will be visible for all to see. In “tree” terminology, the non-fruit-bearing trees will yield fruit.
This approach answers a question posed by commentators. If the words “the trees of the field shall yield their fruit” refers to previously non-fruit-bearing trees, why does the Torah use the phrase “their fruit?” Why didn’t the Torah omit the word “their?” It follows that while the non-fruit-bearing Jew is filled with Mitzvos, for all intents and purposes they are neither evident nor noticeable. In the Messianic Age, however, these individuals’ Mitzvos/fruits will be fully exposed.
This miracle is the antidote to the lack of sub-text. In the Messianic Age we will see the deep-rooted positive feelings embedded within each one of us.
The second miracle that will occur is that the trees will bear fruit the very same day the seeds are planted. One of the characteristics of our exile is that we rarely see the lasting effects of our actions and, thus, fail to appreciate why we should plant our spiritual seeds.  Because we do not see the true consequences of our actions— either good or its opposite—we do not take our responsibilities seriously. We do not recognize the right context for our good deeds; we don’t see what comes next and how our actions really make a difference. We don’t realize the incredible spiritual energy that is released each time we do a Mitzvah. This lack of context will be rectified in the Messianic Age when we will see—literally and figuratively—the cosmic effects of the seeds (read: Mitzvos) that we planted in the past and that we will go on to plant in the future.
The third miracle addresses the problem of inconsistency. In the present day and age, a tree and its fruit are the very symbol of inconsistency. The tree and its fruit are in a state of contrast; one has no taste while the other’s taste is wonderful.  This brings to mind the individual who has no feeling or taste for Judaism but tries to teach it to others. Alternatively, it can refer to one who does good deeds (bears fruit) but lacks sincerity, enthusiasm and life (like a tasteless piece of bark). In the Messianic Age that will all be remedied; the tree and the fruit will have the same taste.  There will be consistency throughout the cosmos. The very text of life will come alive.
Three Pronged Campaign
As we have stated, the shape of the future depends on our actions today. Our challenge now, in these last moments of exile, is to reverse the three Galus maladies by performing the “exercises” prescribed by the Torah for: (a) changing the sub-text by revealing the inner core of our souls, (b) changing the context by opening our eyes to see the whole picture, and (c) by changing the text itself by instilling more soul and vitality in our lives and actions.
How does one achieve all of the above?
While there may be many diverse approaches that deal with each problem separately, there is one supremely straightforward approach to all of them together: the study of Torah, particularly those parts which deal with the concepts of Moshiach and Redemption.
Torah is also called Torah Or-The Torah of Light. Light has the capacity to reveal that which is hidden in darkness. This is particularly true of the inner and mystical dimension of the Torah transmitted by the teachings of Chassidus. Torah enlightens the inner recess of our soul and allows it to come to merge with the surface of our being. Torah is also called Toras Chesed-the Torah of Kindness.  Torah focuses on the positive traits within each and every one of us and teaches us to see and speak about the positive qualities of others. That too helps them actualize their soul’s “delightful fruits.” This is the answer to the first challenge, understanding the meaning of non-fruit-bearing trees that produce fruit.
Torah also opens our eyes to see the world in context. Through the prism of Torah, particularly the parts that deal with Redemption, all world events are illuminated. Torah helps us see how all world events—especially in recent times—are part of a Divine pattern that leads inexorably to the imminent Redemption. Torah provides us with the ability to connect the “planting of the tree” to the production of its “fruit.” Torah helps us connect the dots and see the context.
Torah is also called Toras Chaim-the Torah of Life.  It empowers us to transform the dry and tasteless tree bark that is our mechanical and perfunctory observance of the Mitzvos into joyous, exhilarating and soulful experiences.  The soul of Torah animates our souls and makes our actions consistent with our inner feelings. The tree (i.e., the Mitzvos we perform with our physical beings) itself becomes a source of light and delight.