It is a fundamental requirement of Jewish law that all Jews place a mezuzah on the doorpost of their home. Jewish law actually requires that it be placed on the right side of every room in the home--excluding the bathroom. A mezuzah is a piece of parchment which contains two handwritten paragraphs from the Torah. An average mezuzah scroll cost a mere thirty dollars, but for a Jew its value is priceless.
The mezuzah is believed to provide physical and spiritual protection for the home. The paragraphs written on the parchment contain the essential declaration of Jewish faith--the Shema. It is appropriate to check the mezuzah scrolls on a regular basis to make sure that not even one letter has faded. It is also appropriate to look at the mezuzah and consider what it represents each and every time one walks into a room.