“As a symbol, the Serpent had as many aspects and occult meanings as the Tree itself; the “Tree of Life”, with which it was emblematically and almost indissolubly connected.
In the beginning of their joint existence as a glyph of Immortal Being, the Tree and Serpent were divine imagery, truly.
The Tree was reversed, and its roots were generated in Heaven and grew out of the Rootless Root of all-being. Its trunk grew and developed, crossing the planes of Pleroma, it shot out crossways its luxuriant branches, first on the plane of hardly differentiated matter, and then downward till they touched the terrestrial plane.
Thus, the Asvattha, the tree of Life and Being, whose destruction alone leads to immortality, is said in the Bhagavad-Gita (15.1-2) to grow with its roots above and its branches below.
The roots represent the Supreme Being, or First Cause, the LOGOS;
but one has to go beyond those roots to unite oneself with Krishna, who, says Arjuna, is “greater than Brahma, and First Cause…the indestructible, that which is, that which is not, and what is beyond them” (11.37).
Its boughs are Hiranyagarbha (Brahma or Brahman in its highest manifestations), the highest Dhyani-Chohans or Devas. The Vedas are its leaves.
He only who goes beyond the roots shall never return, i.e., shall reincarnate no more during this “age” of Brahma.”
H. P. Blavatsky
The Mark Of God: Understanding Your "I AM Presence" 