Trinity medallion is at the center of decorative resin wall cross 6" x 9.25". coppery shaded accents and dimensional trim. Enclosed gift card with Trinity sentiment. Trinity Treasures Collection. The Trinity Knot The Celtic Trinity Knot (or triquetra, meaning "three-cornered") is a Christian symbol for the Trinity: God the Father, Son and Holy Spirit. The interwoven circle symbolizes the "whole" created through the unity of the three Persons, a sign of unending life and love.