In this week's Parsha, we find the rewards and the punishments for obeying and for disobeying the laws of the Torah. The Parsha begins by referring to the Chukim and the Mitzvos of Hashem, saying תשמרו ועשיתם אתם"," "you must keep and do them" (ויקרא כ"ו:ג'). This phrase seems to be repetitious. What is the difference between keeping Chukim and Mitzvos and doing them? Actually, we see these same two verbs in a Posuk elsewhere in the Torah (שמות ל"א:ט"ז), concerning Shabbos, where we read "ושמרו בני ישראל את השבת לעשות את השבת," "And Bnai Yisrael shall keep the Shabbos and do (what must be done on) the Shabbos." We thus see that keeping and doing are different. The difference may be between active and passive participation. To "do" is active while to "keep," or to watch or guard, is passive; one must do a Mitzvah which requires action, and must watch and make sure not to violate a Mitzvah that prohibits a certain action. The Torah thus says that both "doing" and "keeping" are necessary for Chukim and Mitzvos. There is, however, another interesting problem that comes up here. The Posuk, as presented above, refers to Chukim, which usually mean laws that we human beings can not fully comprehend, and Mitzvos, which usually mean laws which can be understood and explained. But there is a third category of laws, Mishpatim, which are laws that are obvious and need no explanation. Why aren't the Mishpatim referred to in our Posuk? Interestingly, the Posuk which introduces the punishments for disobeying Hashem's will does refer to Mishpatim along with Chukim and Mitzvos (ויקרא שם פסוק ט"ו). Why then does the Posuk introducing the rewards not make mention of the Mishpatim? It could be because of Hashem's mercy. If one follows the Chukim and the Mitzvos, one already earns a great reward, even if he does not observe the Mishpatim fully. But in terms of Hashem's anger and punishment, it takes three things before He gets angry, meaning that one must violate all three categories of laws before Hashem will get angry. Only then will he send terrible punishments.
No one is perfect. Hashem therefore might wait to punish until one has violated every type of law, but He will not hold back the reward if there is effort. It therefore takes fulfillment of only two categories to allow a person to receive rewards because he has shown effort. Even if he is not able to do everything, it is because no one is perfect - no one can do everything. And one is also not punished until a true pattern has been developed, and one has violated every type of law.