This knot is believed to signify the the Pagan trinity wherein the 3 forms may represent the Mother, Crone, and Maiden. This symbol may also relate to the three Bridgits, the three aspects being Art, Healing, and Smithing. Bridget is one powerful goddess who embodies the three aspects mentioned. There is usually a circle around the triquetra which symbolizes protection, eternity, and the infinite. Circles around the Celtic knots depict spiritual unity.