We are told קְדֹשִׁים תִּהְיוּ, “…You shall be holy…”. (Lev. 19,2) The Torah then commences to tell us how to be holy. This Portion has 51 laws. Interestingly enough, there are only three or four laws that refer to our relationships or our obligations to Hashem. The rest of the laws deal with how one should act and how one should behave towards his fellow man.
Being holy in Judaism does not mean one should seclude himself from society and live in a mystical and spiritual world. For a Jew being holy means to deal honestly and appropriately with other people. If he mistreats others he desecrates the name of Hashem and is not holy.
The famous Rabbi Levi Berditchiv said to fast and to isolate oneself even the non-Jew knows how. To eat in a Halachic way only the Jew knows. A Jew knows there are limitations on what he eats and how he eats. The Jew does not need state laws to prevent him from being cruel to animals. He knows that cruelty to any creature is against the teachings of the Torah.
The Jew knows one must respect and give honor to his elders. He knows education is not only to be able to earn a livelihood but is a lifelong pursuit. All of the mundane necessities of life if done according to the dictates of the Torah are what makes one holy. The fifty one laws in Kedoshim are to help us deal with our daily lives in an Halachic way and that makes us holy.