Seeing that through the knowledge of the Torah man’s soul and mind encompass the Torah and are in turn encompassed by it, the Torah is called food and the sustenance of the soul. For just as material food sustains the body and enters it and is transformed in the body into flesh and blood, by virtue of which a man lives and endures, so it is with regard to knowledge of the Torah and its comprehension by he who studies with concentration until the Torah is grasped by the mind and becomes united with it. (Rabbi Shneur Zalman of Liadi)
If a Jew keeps the commandments close to his or her heart, both learning them and living them in everyday life, I can see how this shapes the person they become. God gave these commandments to a whole nation of people, to keep them as a community. He also founded the nation through experiences that are relived each year during the holidays. Each part of the Law has formed the community to be a particular way, for a particular calling. Its leaders have also made decisions that will help reflect and preserve the spirit and the letter of the Torah, complex as it is, in their generations.
Even if some aspects of the covenant or ritual are hard to understand, this is why the psalmist could call them his freedom and delight. “I will never forget your precepts, for by them you have preserved my life.” (Psalm 119)