We read in the Talmud that the source of all water on earth is the Garden of Eden. After Adam sinned, man was banished from Eden. He was not, however, not cut off absolutely from his former paradise. By immersing himself in the water of the mikveh, Man can again create a link between himself and Eden.

The Midrash tells us that after Adam was expelled, he repented for his sin, and sought to re-establish his bond with Eden. To this end, he sat for an extended period of time in the waters of the river which flows out from the Garden. Even today, when a person immerses in the mikveh, he, too, builds a bond with the sublime level of near perfection that was Adam's before he sinned.

This explains why the waters of the mikveh must come from a natural source, with no intervening vessels. At no point on their path to the mikveh may there be a risk of their being contaminated spiritually. Any contamination would sever the direct link with the waters of Eden.

The Hebrew word “mikveh” signifies a place towards which water flows naturally and gathers in a pool. In practice, the word is used to designate a small, man-made pool in which naturally flowing water can collect, and which is used for immersions when a person becomes ritually contaminated. The word is mentioned in the Torah with this connotation in only one place: “Only a spring or a cistern - a gathering of water - shall remain pure...” (Leviticus 11:36).

Judaism teaches us that our world is a combination of physical and spiritual entities. Each physical phenomenon is a manifestation of a spiritual entity. Man is a delicately balanced composite of the two, body and soul. His body is a physical manifestation of the Divine soul dwelling within it. When a person immerses himself in the water of a mikveh, his soul immerses in spiritual water, is cleansed, and emerges once again pure.

One of the immediately apparent qualities of water is the fact that, at room temperature, it is a liquid. In fact, water is the most common fluid to be found on the face of the earth. The most striking distinction between a solid and a liquid is that the latter adapts itself to the shape of its container. Solids do not change in form. Were our world composed exclusively of solids, there would be no possibility of change. The entire globe would be one solid block of matter not given to alteration.

On the other hand, if the entire globe were composed of liquid alone, it would be in a state of constant change. Nothing would be steady or constant. Life as we know it is a combination of both consistency and on-going change. Every living creature undergoes change, but it nonetheless retains its identity. A full-grown octopus remains an octopus; so, too, a mature redwood tree is identifiable as just that, even after hundreds of years of growth. Humans also undergo many changes; their identities, however, remain constant.

In the Garden of Eden, where Adam lived when first created, the thorn of death first sprouted and brought the barbs of contamination into Man's world. At the same time, Adam longed incessantly to return to Eden, to a world more just, purer, pristine, and far closer to perfection.

Another insight into the topic of spiritual contamination and purity is connected to the process of spiritual cleansing through immersion in a mikveh. As a first step, we must understand how an individual becomes impure. The Torah gives us the details: You shall become contaminated through the following; anyone who touches their carcass will be impure until the evening (Leviticus 11:24).

The Torah then lists several categories of animals, rodents, and insects which contaminate those who come into contact with them. It then carries on: And when they are dead, anything upon which a part of them will fall, shall be contaminated… (ibid. 32).

Life events which create a state of contamination are, on the whole, related to death. Additional causes are imperfections in Man, such as ethical faults or sins. All these are consequences of the sin of Adam, which brought death and other human failings upon the world. Had Adam maintained his lofty moral stature in Eden, there would be no potential sources of contamination in our world.

Death is the natural, inevitable termination of life in this world. It patiently awaits each of us at the end of his path in life. All eventually reach the final stop, each human being, each beast, each flower, each tiny insect. The life-and-death cycle of the universe is all-pervasive. Stars and entire galaxies are born, dissipate, and slowly die, like so much water which flows without end, and is slowly absorbed by the soil and disappears into the earth.