Many times throughout the Torah, we are told to observe the Mitzvos of Hashem. In this week's Parsha as well, we read "את משפטי תעשו ואת חקתי תשמרו," "Carry out My laws and safeguard My decrees" (ויקרא י"ח:ד). But why the redundancy within this statement? Aren't, משפטים, laws, and חוקים, decrees, similar? One well known answer is that משפטים, laws, are the practices that one would have abided by through reason even if they weren't commanded by the Torah, while חוקים, decrees, are the commandments that we follow without fully understanding their purpose. But if we are truly incapable of understanding these commandments, why were they given to us? Isn't there enough to do with the commandments that we are capable of understanding?
Rabbi Dovid Feinstein suggests that the existence of these decrees serves to teach us a lesson about the importance of sometimes not questioning when Hashem wants something of us. We must try to incorporate in ourselves a trusting obedience to all of the Torah's laws. Even though we might see no necessity or purpose whatsoever to some of them, we must obey them nonetheless, realizing that there is a higher degree of meaning that we cannot comprehend. We must understand that we shouldn't always question and thereby base our beliefs only on what we understand. Rather, we must submit to Hashem and obey His will at all times, even when it is difficult to comprehend.
Now that we fully understand the meaning of the word חוקים, decrees, we may correctly translate a Posuk later in the Parsha. The Torah says "ושמרתם את משמרתי לבלתי עשות מחקות התועבת אשר נעשו לפניכם," "You shall keep My safeguards in order not to do any of the abominable decrees that were observed before you" (שם פסוק ל"ד). The Gemara in Yevamos (דף כ"א.) derives from here that one must make safeguards to protect the laws of the Torah; this is one of the sources which allows the Rabbanan to make certain laws. We can see from our original Posuk, though, that the requirement to make safeguards relates to חוקים, decrees. Therefore, we may suggest that the Torah is telling us that if one keeps the safeguards, even those whose purposes are not easy to understand, one won't come to do any abominable acts or transgress any of the laws which normal reasoning alone would also forbid.