Celtic Tree Of Life

The Tree was a central part of early Celtic spirituality. The tree of life symbolizes the cycle of life, death, and rebirth in a sense of the wheel of life. The branches and roots are connecting heaven and the underworld. Also, it can represent the Celtic theme of three worlds, that of the upper for dieties, middle as our physical plane, and lower as the realm of the fey or faeries. This is depicted by the branches that reach to the heavens, the trunk in the center, and the roots below. It's basic overall symbolism is how we are all connected through nature.In Celtic legends of the Gods, trees guard sacred wells and provide healing, shelter, and wisdom.
The tree of life is associated with many cultures other than the Celts a motif in various world mythologies, theologies, and philosophies.

Celtic Shield Knot

Celtic shield knot is like any of the Celtic knots with for distinct corner areas. They usually resemble a square but sometimes they are a square shaped emblem within a circle. As in all Celtic knots there is no beginning or end. The Celtic shield knot idea comes from civilizations more ancient than the Celts. It was a universally used for warding off evil spirits and protection from danger. The symbol is always fourfold based, but within a greater unity.
Shield knots have appeared in cultures around the world and have taken a variety of different forms.
In modern Celtic reconstructionist groups, the shield knot is sometimes invoked as a ward to keep negative energy away. In some traditions, the corners of the knot are meant to represent the four elements of earth, air, fire and water.