In publications and images from the early history of the Church one often finds variations of the symbols of the Alpha and Omega which are the first and last letters of the Greek alphabet. The symbols together represent the Lord God. Apocalypse 1: 8, states, "I am the Alpha and the Omega, the beginning and the end, " says the Lord, "who is and who was and who is coming, the Almighty."
This symbol is often combined with the Chi-Rho (representing Christ) these letters tell Christians that He is the source of life. A symbol that He is the beginning and end of happiness.