In Parshah Eikev, we have the second half - or second third, if you will - of the daily kerias Shema. The last paragraph is really a distinct point, i.e. remembering the redemption from Mitzrayim, but the first two paragraphs have many striking similarities and distinctions. First of all, they seem to us to be somewhat repetitious. The Mishna (Berachos 2:2) explains the content and order of these two paragraphs as follows:
Rabbi Yehoshua ben Korcha said: why, in the mitzva of the recitation of Shema, did the portion of Shema precede that of Vehaya im shamoa? This is so that one will first accept upon himself the yoke of the kingdom of Heaven, the awareness of G-d and G-d's unity, and only then accept upon himself the yoke of the mitzvot, which appears in the paragraph of Vehaya im shamoa.
If the point is to do the mitzvos, and a person is ready to do them, should that not suffice? If a person accepts upon himself the yoke of heaven, does that not automatically mean that he will accept the yoke of mitzvos? After all, aren't they almost synonymous? If a person is willing to do what Hashem commands us to do because he is the ultimate King, then isn't he perforce going to perform the mitzvos?
Additionally, the reward and punishment aspect which is included in this second paragraph is markedly different then the first paragraph. In the first paragraph we speak of total faith and commitment to Hashem even at the price of giving up one's life or possessions. There does not seem to be any indication of reward, and even possibly the contrary: one may end up losing everything because of one's faith in Hakadosh Baruch Hu. Why does this change so drastically in the second paragraph? We also are puzzled by the offering of these rewards and punishments. We know that the Mishna (Avos 1:3) exhorts us to obey Hashem the way a servant would, regardless of reward. There are places where the Torah indicates rewards and punishments, but those are seen primarily as indicators of when we are performing well as opposed to when we are straying. They are a type of positive and negative reinforcement; they are symptoms and signs, but not the purpose. In this paragraph, where we express our core commitment to observing mitzvos , why is the aspect of reward and punishment included?
Let us understand the distinction between these two commitments. The difference between the "yoke of heaven" versus the "yoke of mitzvos" is as follows: The yoke of heaven implies that Hashem's will is the dominant will in the universe, and a command of His must be accepted as such. It means that we don't need to feel or think that the mitzvos are in any way of use, help, or benefit in any way to anyone, neither physically nor even spiritually. The yoke of heaven simply implies that His orders ought to be obeyed as such, period.
But the yoke of mitzvos is a very different type of obligation. True, if one does not accept the yoke of heaven then one really cannot accept the yoke of mitzvos. We need to realize, however, that just as the mitzvos are obligatory because Hashem gave them to us, it is equally true that they also are there to perfect the world. Hashem put us in this world with a mandate, and that mandate is "lovdo olshamra" - to work the garden and to guard against harm. Adam was put into this world in order to develop the world. Hashem has chosen to make us the ones who either bring out the best in the world, or destroy it. The reward and punishment mentioned in this parshah are not merely a feedback mechanism or a reinforcement to spur us to do what's right, rather they are our core understanding of what we're accomplishing. We are the messenger of the Divine to accomplish this.
This is most strongly expressed by Rabbeinu Bchaya (Devarim 27, 26):
"Cursed be he who will not uphold the words of this Torah." This includes all the commandments in the Torah. The meaning of the verse is: a person must acknowledge all the commandments of the Torah as true and emanating from God; he may not exclude a single one of them from his acceptance as such by denying that it is of value to body and soul. He must not view a single commandment as superfluous and meaningless. This is the meaning of אשר לא יקים לעשות אותם. He must be convinced in his heart that all the commandments are worthwhile observing seeing they are all full of meaning to people engaged in studying them.
Thus, our reading of kerias Shema twice a day affirms the following two core aspects of our belief. One is that the world of mitzvos is mandated by Hashem. We do not have the discretion to choose our own mitzvos or deny them. We are obligated to do them whether we understand their meaning or not. The second core belief, expressed in the second part of kerias Shema, is that all of those mitzvos that are mandated by Hashem, and done as such, are activities that bring out the good in the world. They are not whims, chas veshalom, nor are they meaningless commandments; rather they are the core of what nourishes the world. And we must believe that when we do what is good and right, the world blossoms, while refraining from doing so, or do things that are bad or evil, destroys the world. This is complete emuna: both ohl malchus shamaim and ol mitzvos.