Baptism is a rite representing a change of state to purity, which is a requirement to meet God at His appointed place, the Holy Temple. Purity of heart is a requirement to dwell with God in the renewed Eden of the future.

Who may ascend into the hill of Yahweh? And who may stand in His holy place? He who has clean hands and a pure heart, Who has not lifted up his soul to falsehood, And has not sworn deceitfully. He shall receive a blessing from Yahweh, and righteousness from the God of his salvation. This is the generation of those who seek Him, Who seek Thy face — even Jacob. Selah. (Psalm 24:3-6    In the triennial Torah reading cycle used during Second Temple times, Psalm 24 is sung on the Sabbath preceding Yom haKippurim.)

Definitions:

Mikvah (pl. Mikvaot) - A mikvah mayim is a gathering of waters, for our consideration a Biblical baptistery.

Living Water - A pure spring-fed stream, representing the river that flowed out from Eden to water the earth, especially parts of the Jordan (Yarden - Descending from Eden) River.

And God said, Let the waters under the heaven be gathered into one place, and let the dry land appear: and it was so. And God called the dry land Earth; and the gathering of waters (mikvah mayim) he called Seas: and God saw that it was good. (Genesis 1:9-10)

There are six grades of baptisteries (mikvaot) found in the Torah; a study of them is found in the Mishnah, Tractate Mikvaot. Each is for specific kinds of baptism (ritual purification), required at specific times. John the baptizer was particularly involved with the baptism of repentance in the highest level of mikvah - a portion of the Jordan River called living water, apparently during the Days of Awe preceding Yom haKippurim (Day of the Atonements).

Original, intermediate, and final sanctuaries:

Adam walked with God in the Garden of Eden; he was pure until he fell, and was exiled from Eden. A river descended from Eden and watered the earth.

And the Lord God took the man, and put him into the garden of Eden to tend it and to keep it. And the Lord God commanded the man, saying, Of every tree of the garden thou mayest freely eat: But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest of it thou shalt surely die. And the Lord God said, It is not good that the man should be alone; I will make him an help meet for him. And out of the ground the Lord God formed every beast of the field, and every fowl of the air; and brought them to Adam to see what he would call them: and whatever Adam called every living creature, that was its name. (Genesis 2:4-19)

After three millenniums, God established a Tabernacle, followed by a Temple; this was God’s appointed place (moed - Exodus 27:21) for man to meet with Him at His appointed times (moedim - Leviticus 23:2). It was to be like a miniature Garden of Eden, devoted totally to the service of God, where everything pertaining to man's fallen state would be excluded. Purity was a qualification for entering the Tabernacle or Temple (Numbers 19:20). After becoming defiled by contracting certain diseases, having various fluid discharges, touching a corpse, etceteras, one was required to be baptized (immerse in a mikvah) before entering; such an immersion represented a change in state from unclean to pure. The picture is of one loosing his contamination from the world of sin, through the water that flows from Eden, to qualify for entering the place where God dwells with man.

"And let them make me a sanctuary that I may dwell among them." (Exodus 25:8)

There is a river, the streams of which shall make glad the city of God, the holy place of the tabernacles of the Most High. (Psalm 46:4)

The Temple was commanded to be made exactly like the pattern in heaven. Yeshua ascended into the heavens to prepare a place for us. This prepared place, that the Temple was patterned after, will come down from the heavens to a renewed earth (Revelation 21:1-3); it will be called the New Jerusalem, and it will be in Eden. We will eat there of the tree of life that was forbidden to Adam after his fall, and drink of the living water!

Who serve unto the example and shadow of heavenly things, as Moses was admonished of God when he was about to make the tabernacle: for, See, saith he, that thou make all things according to the pattern shewed to thee in the mount. (Hebrews 8:5)

And if I go and prepare a place for you, I will come again, and receive you unto myself; that where I am, there ye may be also. (John 14:3)

And I saw a new heaven and a new earth: for the first heaven and the first earth were passed away; and there was no more sea. And I John saw the holy city, new Jerusalem, coming down from God out of heaven, prepared as a bride adorned for her husband. And I heard a great voice out of heaven saying, Behold, the tabernacle of God is with men, and he will dwell with them, and they shall be his people, and God himself shall be with them, and be their God. (Revelation 21:1-3)

And he showed me a pure river of water of life, clear as crystal, proceeding out of the throne of God and of the Lamb. In the midst of its street, and on each side of the river, was there the tree of life, which bore twelve kinds of fruits, and yielded her fruit every month: and the leaves of the tree were for the healing of the nations. And there shall be no more curse: but the throne of God and of the Lamb shall be in it; and his servants shall serve him: (Revelation 22:1-3)

As coming out of the waters of the baptistery (mikvah mayim) represents a birth - being born through the waters of Eden, by the physical we picture the spiritual - being born through the Spirit of Messiah.

Yeshua answered and said to him, "Truly, truly, I say to you, unless one is born again, he cannot see the kingdom of God." Nicodemus said to Him, "How can a man be born when he is old? He cannot enter a second time into his mother's womb and be born, can he?" Jesus answered, "Truly, truly, I say to you, unless one is born of water and the Spirit, he cannot enter into the kingdom of God. "That which is born of the flesh is flesh, and that which is born of the Spirit is spirit. (John 3:3-6)

The like figure to which even baptism doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience toward God,) by the resurrection of Jesus Christ: (1 Peter 3:21)

Therefore we have been buried with Him through baptism into death, in order that as Christ was raised from the dead through the glory of the Father, so we too might walk in newness of life. (Romans 6:4)

Christ also loved the church, and gave himself for it; That he might sanctify and cleanse it with the washing of water by the word, That he might present it to himself a glorious church, not having spot, or wrinkle, or any such thing; but that it should be holy and without blemish. (Ephesians 5:25-27)

Ritual uncleanness primarily involves the soul, rather than the body (Leviticus 11:44). Ultimately, all uncleanness, including death and human imperfection, is a result of Adam's sin.

The Talmud teaches that all the water in this world had as its source the river from Eden. The Mikvah Mayim is our primary contact with the Garden of Eden. When we immerse in it, we are born again - symbolically from the Mem for Mayim, picturing our spiritual birth by the Word of God.

Technicalities of Mikvaot:

Six degrees of mikvaot (gatherings of water), each superior to the former:
(Talmud, Seder Tohorot, Tractate mikvaot, Chapter 1, Mishnaot 1-8)
1. Water of pits (if an unclean person drinks thereof, the next drinker becomes unclean)
2. Water of rain drippings (valid for the * * *
3. The mikvah (valid for immersion if 40 se'ahs / 200 gallons)

"Only a spring and a pit, a gathering of water, it shall be clean" - Lev 11:36
    Ach - not a vessel
    Ma'yan - water must be natural
    U'Bor - receptacle may be man made
    Mikveh - water cannot be flowing
    Mayim - no other kind of liquid
    Yihyeh tahor - receptacle and all ducts must be undefilable

    The sea is always a valid mikvah (Chapter 5, Mishnah 4)

    These render the mikvah invalid: (Chapter 7, Mishnah 2)
    a.  drawn water
    b.  water used for pickling or seething
    c.  unfermented wine (grape juice)

4. The fountain (valid for immersion when pooled) Water from a fountain that is made to pass over a trough becomes invalid (Chapter 5, Mishnah 1)
5. Smitten water (hot spring - valid for immersion when running)
6. Living water (clear spring fed stream - valid for immersion of persons with running issue, sprinkling of lepers, and preparation of water of purification)

Method of immersion:

The person goes completely into the water, with no clothing, jewelry, caked dirt, or anything to keep the water from wetting every part of the body. Once in the water, arms, legs, toes, and fingers are spread to ensure full contact with water. One must go in deep enough that his hair does not float on the surface. No one else may be touching the one immersing.

One traditionally immerses three times, and has a witness to verify proper total immersion.

A proclamation is to be made as to the purpose of the immersion (i.e., for the dead - contact uncleanness, for conversion - entering new life, etc.) and the statement may include "in the name of . . . ". This proclamation is made by the one immersing himself, indicating his intent. An immersion is neither validated nor invalidated by stating "in the name of . . . (Jesus; Father, Son and Holy Spirit; etc.)"

Immersion is invalidated by the use of a defiled mikvah (such as a man-made tub), impure water (such as from piped water systems), clothing or jewelry being worn, incomplete immersion, or stating incorrect purpose.

Required times to immerse in a mikvah and put on clean clothes (partial listing):

Before entering the Holy Temple (hence before the pilgrimage festivals for men),
and (traditionally, by extension) before going to synagogue on Sabbath,

The right of entry into the future Eden (Paradise) of God is by grace through faith. A pure heart is the requirement. Baptism is a physical picture of a spiritual reality. However, it is suggested that we should not be so arrogant as to think that we may freely change God’s planned picture.