The following is an excerpt from myjewishlearning.com. Take note of the Christian water baptism parallel concerning the Mikveh bath necessary to convert to Judaism:
“The water of the mikveh is designed to ritually cleanse a person from deeds of the past. The convert is considered by Jewish law to be like a newborn child. By spiritually cleansing the convert, the mikveh water prepares him or her to confront God, life, and people with a fresh spirit and new eyes--it washes away the past, leaving only the future. Of course, this does not deny that there were good and beautiful aspects of the past. But, in the strictest religious sense, that past was only prologue to a future life as a Jew.
There is a second layer of meaning to mikveh. It marks the beginning of the ascent to an elevated religious state. This function of mikveh goes beyond the basic purpose of purification. anthropologists refer to this threshold of higher social status as "liminality." The person at this moment of transition is a "liminal" or "threshold" person. The liminal state is common to virtually all persons and societies, ancient and modern, and it marks a move to an altered status or to a life transition.
Entering adulthood from adolescence, for example, requires a tunnel of time, a rite of passage, a liminal state that acknowledges by symbolic acts the stark changes taking place in one's self-identity, behavior, and attitude. In a sense, it is nothing short of the spiritual drama of death and rebirth cast onto the canvas of the convert's soul.
Submerging into waters over his/her head, he/she enters into an environment in which one cannot breathe and cannot live for more than moments. It is the death of all that has gone before. As he/she emerges from the gagging waters into the clear air, he/she begins to breathe anew and live anew--as a baby struggling to be born. If we take this graphic metaphor a step further, we can sense that the mikveh is a spiritual womb. The human fetus is surrounded by water. It does not yet live. The water breaks in a split second and the child emerges into a new world. "As soon as the convert immerses and emerges, he/she is a Jew in every respect" (Yevamot 47b).
The site also includes information about receiving a new name during the Mikveh/Rebirth experience: “The newborn Jew takes on a
Hebrew name, but a given name only is not sufficient to locate a person within the Jewish tradition. When Jews sign legal documents or are called up to the Torah, their parents' names are appended to their Hebrew names to locate them in Jewish spiritual space. A convert traditionally adopts Abraham and Sarah as spiritual parents and in legal situations is referred to as "ben Avraham Avinu," "son of our Father, Abraham," or "bat Sarah Imenu," "daughter of our Mother, Sarah."
There are similarities between the Jewish conversion and the Christian spiritual rebirth at water baptism. The main difference is one is a true rebirth the other a symbolic act.