The Mikvah
Two complimentary reasons emerge when contemplating the various times we are instructed to go to themikvah, the Jewish ritual bath. TheTorah prescribes going to themikvah in order to become ritually pure after a temporary state of ritual impurity, or when a person or object changes status, such as when a non-Jew converts or when a vessel changes ownership from a non-Jew to a Jew. Though not a decree from the Torah, many men go to a mikvah at the end of the week in preparation for Shabbat. or a holiday. A bride immerses before her wedding day as do many grooms. All the above reasons have in common their being times of transition, from one spiritual state to another.
Main Article link :
http://www.chabad.org/theJewishWoman/article_cdo/aid/335957/jewish/Mikvah-The-Art-of-Transition.htm
Read more : (family perspective)
http://www.chabad.org/library/article_cdo/aid/680218/jewish/The-Mikvah.htm