The Introduction 
Before the Torah introduces the admonition against emulating the abominable behaviors of the Egyptians and Canaanites, the Torah inserts the following: 
“Carry out My laws and safeguard My decrees to follow them; I am G‑d your G‑d. You shall observe My decrees and My laws, which man shall carry out and you will live by them – I am G‑d.” 
What does the Torah mean when it says, “…and you will live by them?” 
The Talmudic Sages (Sanhedrin 74a) derive from this verse that the Mitzvos-Divine commandments were given for the sake of life, not death. With the exception of three cardinal sins (Idolatry, forbidden relations and murder) the preservation of life takes precedence over the performance of a Mitzvah.  For example, one whose life may be at risk by fasting on Yom Kippur does not have to fast, and indeed, is told not to fast. 
The question can be asked, why does the Torah introduce the concept of the supremacy of life over the observance of a Mitzvah as a preface to enumeration of the forbidden relationships? 
This is puzzling, as forbidden relationships are actually one of the exceptions to the general rule. If one is threatened with death or committing adultery, for example, he may not violate this commandment; he must die rather than submit. Why then does the Torah preface the “life above all else” imperative to a section where that imperative does not apply? 
Rashi Anticipated the Question 
It is possible that Rashi anticipated this question and it may have prompted him to explain that the reference to living here is to the World-to-Come. Rashi supports this interpretation with the following argument: “If you shall say that it refers to this world, is it not true that he will die in the end?” 
At first glance, this proof is hard to grasp. What does Rashi mean that ultimately he will die? Why can’t the Torah mean that by observing the commandments people will live longer and more wholesome years? Alternatively, why didn’t Rashi cite the Talmud’s explanation that we should live and not die in the observance of Mitzvos? 
It may be conjectured, that Rashi was referring specifically to the commandments that follow in the Biblical text, i.e., the forbidden relationships, concerning which one must die rather than transgress. Rashi therefore argues how can the Torah be referring to life in this world if one is required to surrender that life to avoid a forbidden relationship?  Rashi therefore concludes that with respect to these commandments the meaning of “…and you will live by them” is in the life in the World-to-Come. 
World-to-Come: Eternal Life on Earth 
Taken at face value Rashi seems to be alluding to the afterlife of the undying soul. However, upon deeper reflection Rashi may actually be referring to the period in the Messianic Age when the dead will come back to life and we will all enjoy eternal life in this physical world. This period is referred to as Techiyas Hameisim-the Resurrection of the Dead. 
Hence, all Mitzvos are associated with life. In this pre-Techiyas Hameisim period, most Mitzvos demand living life to the fullest in the most literal sense while some apply to the future. The common denominator is that all of these Mitzvos are associated with life in this physical world. 
The question can now be reversed. Why would the Torah introduce the concept of living with our Mitzvah observance in the context of a Mitzvah which relates to life in the future? 
Preparing for the Future 
The answer is that all the Mitzvos we perform now prepare us for the Techiyas Hameisim era. 
This premise is rooted in the words of the Tanya [the classic work of Chassidus, authored by the Alter Rebbe, Rabbi Schneur Zalman of Liadi, the founder of the Chabad movement]. 
In chapter 36, the Alter Rebbe explained that the purpose of G‑d’s creation of our world is that “G‑d desired an abode in the lowest realms,” referring to our physical world.  We inhabit a world in which G‑d’s presence is utterly concealed, and He created this world of spiritual darkness with the intention of reversing that concealment and darkness so that His presence should ultimately be revealed. 
The fulfillment of G‑d’s plan to make the world an abode for Himself will come to pass in the Messianic era, the period for which the world was originally created, and especially the period after the resurrection of the dead.  Then G‑dliness will be manifest throughout the world and all the nations on earth will experience Divine revelation 
The Alter Rebbe continues to elaborate on this theme in Chapter 37: 
“Now this ultimate perfection of the Messianic era and [the time of] the resurrection of the dead, meaning the revelation of Ein Sof-light in this physical world is dependent on our actions and [divine] service throughout the period of exile. For it is the Mitzvah itself that causes [i.e., creates] its reward. For by performing [the Mitzvah] man draws the revelation of the blessed Ein Sof [infinite]-light from above downwards to be clothed in the physicality of this world.” 
After a lengthy analysis of how the Mitzvah reveals unadulterated G‑dliness into the physical world, the Alter Rebbe continues: 
“It follows, therefore, that the purpose of the Messianic Era and of the resurrection of the dead, namely, the revelation of His glory and Divinity , and the banishment of  the spirit of impurity  from the earth, is entirely dependent on [our] drawing down His G‑dliness and the blessed Ein Sof-light upon all the 248 limbs of the vital soul of all Israel by the vital soul's performance of all the 248 positive Mitzvos and [this purpose is also dependent] on [our] banishing the spirit of impurity from the vital soul of all Israel by the vital soul’s observance of all the 365 prohibitive Mitzvos.” 
In summary, whenever we perform a Mitzvah with the energy from our vital, animating soul and body with the use of a physical object we reveal G‑d’s infinite light in the physical world. The Messianic age, and particularly, the period following the resurrection of the dead, is when we will all see the fruits of our labors. 
Thus, when we perform a Mitzvah we are actually introducing the Divine energy that will become fully manifest in the future resurrection-of-the-dead era. 
This explains why the imperative to live with most Mitzvos (and not die because of them) is connected to the life of the future (the reward for the Mitzvos that require sacrificing our lives), for in truth, each and every Mitzvah introduces us to the life of the future. When we do a Mitzvah today we internalize the light of the future. 
One can add to the above an important thought. Now after thousands of years of Mitzvos performed by countless individuals under the most strained conditions, we have already elicited virtually all of the Ein Sof-light of the future age of the resurrection. 
Quality of Life or Life’s Quality 
Where do we see evidence of this unprecedented phenomenon of infinite Divine light ready to be revealed in the present era? 
The answer is that we see it, paradoxically, in two opposite examples. 
First, never before have we seen the medical advances that cure illnesses, remove pain, improve the quality of life, prolong it and even portend a time when we will be able to live indefinitely. The potential to live to well over a hundred is already here and the notion of eternal life is not so remote in the minds of even the most secular of scientists. Never before have we seen so many advances in the field of life. This phenomenon is clearly indicative of the future period of eternal life. However, since we are still in exile—albeit, on the threshold of Redemption—we see the effects of this revelation without seeing its source. 
The Rebbe’s exhortation to “open our eyes” can be applied to our need to look at the latest extraordinary changes in the world and attempt to see their source. 
Second, we are also, ironically, witness to the greatest erosion of human life. Whether at the beginning of life or near its end, our society today is engaged in the worst possible assault on life’s sanctity. The trite expression “quality of life” is used to deny the fact that life itself is the greatest quality, for it is an expression of the Divine in the physical realm and provides with the opportunity to do a Mitzvah. 
As discussed in previous essays, whenever there is an explosion of positive energy in a certain direction, we will also witness a parallel surge of negative energy. This phenomenon is based on the words of King Solomon in Ecclesiastes that G‑d creates parallel forces of good and evil. As long as we haven’t totally left exile, evil asserts itself, particularly in the area where goodness and holiness are most pronounced. Precisely because we are on the very cusp of the age of eternal and unprecedented quality of life we are also experiencing the greatest erosion of and assault on life. 
Three Lessons: Open Our Eyes, Savor and Fill 
The lesson for us in these extraordinary times is threefold: 
First, we should open our eyes to the reality of the life embracing/assaulting phenomenon as evidence that we are about to enter into the period of eternal life. 
Second, we should do everything in our power to savor and treasure every moment of life as G‑d greatest gift to us. We should do everything in our power to discourage the epidemic of threats to life from the medical community by educating people about the true value of life. Whenever there is a question about undergoing a medical procedure that can impact life, only a competent Halachic authority should be consulted for guidance. 
Third, we should fill every precious moment of life with Toras Chaim-the Torah of Life, the life affirming power of Torah study and Mitzvah observance, suffused with enthusiasm and revel in the knowledge that we will imminently see the fruit of our labor, with the immediate Redemption.