The Chi-Rho Symbol
A circle with three straight lines drawn through its diameter may be seen on the street leading from the harbor of ancient Ephesus up to its great theatre (Acts 19:29). From the time the circle was etched there, on the surface of the marble street, Christians arriving by sea knew they had brothers and sisters in Ephesus.
To a pagan passerby the circle might have looked like a rather simple graffito, perhaps with meaning, perhaps not. But to a Christian the lines in the circle formed a X (Chi), the first letter of the word Christ, in the Greek language. The lines also described a P (Rho), the second letter of the same word in Greek.
In later, more stylized renditions of this Chi-Rho symbol, the P (Rho) was clearly inscribed and the letters Alpha and Omega in Greek were sometimes written from left to right in the circle. These letters, the first and the last of the Greek alphabet, referred to Jesus as “the beginning and the end” (Rev. 1:8, 17) and, therefore, co-equal and co-eternal with God the Father (Isa. 44:6).