An excerpt from Rabbi Kaplan's "The Handbook of Jewish Thought"
The commandments can be divided into two categories, decrees (chukim) and ethical laws (mishpatim).
The ethical laws are necessary for the preservation of society. As such, they provide the basis for the moral structure of Judaism.
God's decrees (chukim) are commandments for which there is no apparent reason. To some degree, these serve to test our allegiance to God in observing His commandments even when not dictated by logic.
There is also a third category, midway between the above two, known as "testimonies" (edut). These have no moral basis, but are inherently logical insofar as they serve to remind us of important religious truths or key events in our history. Included in this group are the various holidays, as well as such commandments that bear "witness" to the important concepts of Judaism.
Even where the true reason for a commandment of law is not known, we should strive to understand its benefits and symbolism. Moreover, even where the basic reason for a commandment is known, we should attempt to understand the logic of its detailed laws.
We cannot depend on the perceived reason to change any law.
Nevertheless, even where an apparent reason for a commandment is known, we cannot depend on the reason to change or restrict any law. This is even true where the reason is specified in the Torah, since there may be other reasons that are not revealed. It is also possible that the laws may involve subtle arguments, not readily ascertained by logic or experience.
It is likewise forbidden to hold God to any reason that we may attempt to give for His commandments. Thus, for example, God commanded that when one finds a bird's nest, he must send away the mother before taking the eggs or young. However, it is forbidden to pray that God should have mercy on us just as He had mercy on a bird's nest. Any reason that we might give for a commandment, no matter how logical, falls short of its infinitude of meaning.
It is for this reason that God did not include the reasons for the commandments in the Torah, and did not reveal them to any mortal in this world other than Moses. Had they been revealed, an imperfect understanding of such reasons and of one's own nature may have lead people to make unwarranted personal exceptions to the commandments.
We must therefore be equally careful to observe all of God's commandments. To profess to believe in a divinely revealed Torah, and at the same time to choose commandments according to one's own judgment, is to claim to be greater than their Giver.
For Our Own Good
God is inherently perfect, and it is therefore obvious that He did not give any of the commandments for His own needs. It is thus written, "If you are righteous, what do you give Him? What does He receive from your Hand?" (Job 35:7).
It must therefore be concluded that God gave the commandments for a purely altruistic motive, for the sole good of the recipients. It is thus written, "Keep God's commandments… for your own good. Behold, the heavens belong to God your Lord… along with the earth and everything in it" (Deut. 10:13, 14).
The commandments were therefore given as a means through which God would be able to fulfill His altruistic purpose in creation, and are all primarily for the benefit of those who observe them. It is thus written, "God commands us to keep all these decrees… for our eternal good. It shall be righteousness for us if we observe and keep all this commandment before God our Lord, as He commanded us" (Deut. 6:24, 25).
Since the commandments were given for man's ultimate benefit, they were made difficult enough to present a challenge, but not so difficult as to make their observance prohibitively burdensome. God thus said, "This commandment, which I give you this day, is not too hard for you, neither is it far off" (Deut. 30:11).
In giving the commandments, God was cognizant of the fallibility of man. It is thus taught that "the Torah was not given to ministering angels." The commandments were thus conceived in such a way that man should not find it impossible to observe them. It is taught, "God does not act as a tyrant toward His creatures."
The main benefit of the mitzvot is to bring a person closer to God.
The most difficult commandments are therefore not those which involve our relationship with God. Rather, they are those which are required to maintain an orderly society. It is not God who makes the commandments difficult, but man's moral weaknesses.
The main immediate benefit of the commandments is in the spiritual realm; obeying the commandments brings a person closer to God. Each commandment acts as a nourishment for the soul, strengthening it, and increasing a person's spiritual fortitude.
Conversely, sin detracts from one's perfection and separates him from God. It is thus written, "Only your sins have separated you from your God" (Isaiah 59:2).
Sin is therefore like poison to the soul. The prohibitions of the Torah were given by God so as to protect us from this spiritual poison.
Plan for Creation
Just as God created a self-sustaining system of physical law, so He created a self-sustaining system of spiritual law. God conceived creation so that man's good comes, not as a reward for his action, but as a direct result of his action. It is thus written, "Righteousness guards the one who is upright in his ways, but wickedness overthrows the sinner" (Proverbs 13:6).
Every human act is therefore reflected spiritually on high. Man's own deeds are thus the means that generate the spiritual closeness that is his ultimate reward.
On a universal scale, the commandments serve to fulfill God's purpose in creation. They thus enhance God's relationship with His universe.
Therefore, the commandments lead to the manifestation of God's absolute unity in the universe, even in the physical world.
Israel thus becomes the means through which God's essence becomes more strongly revealed in the world. It is thus written, "[To] give strength to God is the duty of Israel His pride" (Psalms 68:35).
Thus, although the average person may not realize it, the commandments serve the highest purpose in God's plan for creation. They are an essential part of the invisible cosmic drama through which this plan is fulfilled.
Therefore, if a person understands the true spiritual nature of the universe, including the nature of good and evil, he will readily understand the significance of all the commandments. It was in this manner that the Patriarchs understood the Torah before it was given, and to a large measure, observed all its commandments. This is also why the true reasons for all the commandments will be obvious in the World to Come, when all truth will be revealed.
Pleasant and Peace
Although the primary benefit of the commandments lies on the spiritual plane, they also provide a great many mundane benefits.
A great number of the commandments deal with man's relationship with his fellow human, and are necessary for the preservation of a harmonious society. Thus, the basis of the Torah is the maxim, "What is hateful to you, to your neighbor do not do." It is written, "You shall love your neighbor as yourself" (Leviticus 19:18), and it is taught that this is the prime rule of the Torah. It is similarly written, "[The Torah's] ways are ways of pleasantness, and all its paths are peace" (Proverbs 3:17).
The ritual commandments serve the purpose of sanctifying our lives and bringing us closer to God. They penetrate every nook and cranny of a person's existence, hallowing even the lowliest acts and elevating them to a service to God.
The mitzvot sanctify every aspect of life -- eating, dressing and business.
Thus, the multitude of laws governing even such mundane acts as eating, drinking, dressing and business, sanctify every facet of life, and constantly remind one of his responsibilities toward God.
Every commandment therefore serves to make us more holy and Godly. Before observing many of the commandments, we therefore recite a blessing including the words, "Who has mead us holy through His commandments." God likewise said that, "you should remember and keep all My commandments, and be holy to your God" (Numbers 15:40).
The many rituals associated with daily life also serve to teach self-discipline. It is thus taught, "When Israel is occupied with the Torah and commandments, they master their desire, and are not mastered by it." It is likewise written, "You shall remember all God's commandments and keep them, and not stray after your heart and after your eyes, by which you are led astray" (Numbers 15:39).
The commandments also serve to maintain the identity of the Jewish people, keeping them apart from the gentiles. With regard to many laws, God thus states, "I am God your Lord, who has set you apart from the nations" (Leviticus 20:24).
The many rituals also provide opportunities for communal observance and fellowship. Individuals are thus able to identify with the community at large.
The commandments also serve to unify the Jewish people by constantly reminding them of their unique history. There is the constant reminder, "That you may remember the day you left Egypt all the days of your life" (Deut. 16:3). Moreover, remembering our unique history also serves to remind us of our unique responsibilities.
The commandments also serve in a pedagogic capacity, transmitting God's teachings from one generation to the next. The Torah thus states that the Israelites should recall the commandments, "So that their children who have not known, may hear and learn to fear God our Lord" (Deut. 31:13). It is likewise written, "[God] gave a solemn charge to Jacob, and established a law in Israel, which He commanded our fathers to teach their children, so that it may be known to future generations, to children yet unborn; and these would in turn repeat it to their children": (Psalms 78:5,6). This is of the highest importance, since it is only such constant transmission that can guarantee the continuance of our faith.
The commandments therefore act as a survival mechanism, enabling Judaism to remain vital, even through the harshest persecutions. Indeed, this is an indication of the Divine nature of the commandments. They have kept the Jewish people alive for countless generations, while a single generation's lapse has led to major spiritual and physical debilitation of the Jews.
The commandments therefore set limits through which a person can fulfill the Divine purpose while living in a world that is essentially hostile toward it. Through the commandments, one can be part of the world, and at the same time, dedicated to the spiritual.
Above and beyond all the meager reasons that we can give for God's commandments, there is an infinitude of depth known only to Him. God thus said, "My thoughts are not your thoughts; you ways are not Mine… For as the heavens are higher than the earth, so are My ways higher than your ways, and My thoughts than your thoughts. But the rain and snow descend from heaven, and return not without watering the earth, making it blossom and bear fruit, providing seed to sow and bread to eat, so shall the word that emanates from My mouth not return to Me void, without accomplishing My purpose, and succeeding in furthering My goal for it" (Isaiah 55:8-11).
From "The Handbook of Jewish Thought" (Vol. 1), Maznaim Publishing. Reprinted with permission.