Mikveh: Jewish ritual immersion in water

A recent post on Junior Ganymede mentions the ritual bath called a mikveh where Jews practiced ritual immersions in pools of water. The parallels to Christian baptism (which means to dip or immerse) are many. In both rituals the purpose of the immersion is a symbolic cleansing or refreshing. Anciently, immersion in a mikveh was required for those converting to Judaism.

Today, these are the modern cases in which a mikveh is used:

by Jewish women to achieve ritual purity after menstruation or childbirth;
by Jewish men to achieve ritual purity (see details below);
as part of a traditional procedure for conversion to Judaism;
to immerse newly acquired utensils used in serving and eating food.

The Wikipedia article I’ve been referencing here cites a source that says “The existence of a mikveh is considered so important in Orthodox Judaism that an Orthodox community is required to construct a mikveh before building a synagogue, and must go to the extreme of selling Torah scrolls or even a synagogue if necessary, to provide funding for the construction.” (Berlin, Meshib Dabar, 2:45)

These ritual immersions can happen many times throughout the year for many reasons. It was a powerful physical reminder of keeping oneself clean. Early Latter-day Saints practiced baptism in a similar manner by getting rebaptized prior to new covenants and ordinances and even for health reasons. Rebaptisms were done away with shortly before the 20th century.

Although not as profound as frequent physical immersion, Latter-day Saints today see their weekly sacrament ritual as deeply related to their baptismal covenants and a source of renewal and rededication.

I found this interesting quote from a book titled Becoming a Jew (Jonathan David Publishers, Inc.) that reminds me of Alma’s preaching in Mosiah 18:

What physical act could a person perform in order to symbolize a radical change of heart, a total commitment? Is there a sign so dramatic, dynamic, and all-encompassing that it could represent the radical change undergone by the convert to Judaism?
Jewish tradition prescribes a profound symbol. It instructs the conversion candidate to place himself or herself in a radically different physical environment–in water rather than air. This leaves the person floating–momentarily suspended without breathing–substituting the usual forward moving nature and purposeful stride that characterize his or her waking movements with an aimlessness, a weightlessness, a detachment from the former environment. Individuality, passion, ego–all are submerged in the metamorphosis from the larval state of the present to a new existence.
Ritual immersion is the total submersion of the body in a pool of water. This pool and its water are precisely prescribed by Jewish law. Immersion, tevillah, is the common core component of every [traditional] Jewish conversion process, for male and female, adult and child, ignoramus and scholar. It is sine qua non, and a conversion ceremony without immersion is unacceptable to the traditional religious community and simply not Jewish in character.”
Online reference