The Tree of Life, sometimes referred to as the World Tree or the Tree of Knowledge, is a mythological concept that appears in the stories of many cultures around the world.

While mythologies about the Tree of Life vary from culture to culture, in general the Tree of Life symbolizes a source of wisdom about the physical and supernatural worlds. In most cultures, it connects the earthly, or material world of humans to the heavenly, or supernatural, world of the gods. In addition, the Tree of Life is foundational to supporting all life.

To the Ancient Egyptians, the Tree of Life represented the hierarchical chain of events that brought everything into existence. In Egyptian mythology, earth and sky were said to have emerged from the Tree of Life. 

To the Celts the tree of life represents the afterlife, and connection between the earth and heaven. The bond and affection to trees is so deep that Celts believed the actual trees were their ancestors, gatekeepers to the Celtic Otherworld. As such, the Tree of Life in Celtic Culture is sacred.

In the Bible, the Tree of Knowledge is similar to the Tree of Life as a source of universal wisdom.

In the Book of Genesis Adam and Eve were not supposed to eat the fruit from the Tree of Knowledge. However, later in the Bible, in the Book of Revelation, human beings are shown how they can safely access the wisdom of Tree of Knowledge, which is then referred to as the Tree of Life. Essentially, if they followed God’s commands, they could earn the right: “Blessed are those who wash their robes, so that they may have the right to the Tree of Life and that they may enter the city by the gates.” (Revelation 22:14)

To our Modern World: the Tree of Life provides the framework for much of our modern understanding of biology because it reveals the diversity of life as well as the historical basis for similarity and differences among organisms.

Most famous Tree of Life in existence

The Tree of Life (Shajarat-al-Hayat) in Bahrain is a 9.75 meters (32 feet) high. Prosopis cineraria tree that is over 400 years old. It is on a hill in a barren area of the Arabian Desert, 2 kilometers (1.2 miles) from Jebel Dukhan, the highest point in Bahrain, and 40 kilometers from Manama.

List of Trees of Life by Wikipedia:

Some thoughts in German