Is a physical act of submission and cleansing, symbolizing a greater submission and spiritual cleaning where one's sin, uncleanness, and separation from Yahweh is removed as far as the east is from the west (compare Numbers 19:1-22, Psalm 103:12). Mikvah or immersion in Ruach haKodesh (the Set-Apart Spirit), is that which is necessary for Yahshua (the return of salvation), for it is the outpouring of Yahshua's power upon his people, granting the power to heal, prophesy, cast out demons, and turn the nations to repentance. Atonement itself and the subsequent "outpouring of Yahshua's Nature or Spirit upon one's life" results from a sincere heart and immersing one's self under the covering of Yahshua's Name or Authority (1Sam.16:7, Lk.8:15) as pictured by the physical action of cleansing and submission. Scriptural mikvah is not into a religious organization, but into the kehillat or assembly of those believing or placing their trust upon Israel's Mashiyach (see Mt 16:18).
To establish an age, before which one is not accountable for their sins, runs contrary to the teachings of the Tanakh(Ezek 18:20,21, Prov 20:11), the same as to establish an age before which one is not permitted to mikvah or immerse for their remission. Once a youth understands the concept of sin, repentance, and Yahshua's atonement, one MUST NOT discourage mikvah, or deny them this opportunity (see Acts 16:29-34, Matt 18:3-6).