Legends of The Tree of Life

1. The Assyrians-
To the Babylonians, The Tree of Life had magical fruit, which could only be picked by the gods. Dire consequences befell any mortal who dared to pluck from it. The Tree found its way into the Judeo-Christian legend of Adam and Eve...
~ George Sassoon and Rodney Dale, The Manna Machine

2. The Celts-
When a Celtic tribe cleared a new land for settlement, they always left a great tree in the middle, known in Ireland as the "crann bethadh", or Tree of Life, it embodied the security and integrity of the Celtic people.
Chieftains were inaugurated at the sacred tree, for, with its roots stretching down to the lower world,and its branches reaching to the upper world, it connected him with the power of both the heavens and the worlds beneath.
~ Mara Freeman 1998

3. Judeo-Christians-
In the Book of Genesis, The Tree of Life is planted by God in the Garden of Eden (Paradise), the fruit gives everlasting life.
God also planted the "Tree of Knowledge of Good and Evil" (Genesis 2:9). After eating from the "Tree of Knowledge of Good and Evil", Adam and Eve were exiled from the Garden of Eden to prevent them from eating of the Tree of Life.
~ Wikipedia

4. The Kabbalists-
The Tree of Life, is a mystical symbol used in the Kabbalah of esoteric Judaism to describe the path to God and the manner in which He created the world.
The Kabbalists developed this concept into a full model of reality, using the tree to depict a map of creation. The tree of life has been called the "cosmology" of the Kabbalah. Some believe the Tree of Life in the Kabbalah corresponds to the Tree of Life mentioned in Genesis.
~ Wikipedia

Image: The Visionary Art of Willow Arlenea - Goddesses