The early Christians used the letter χ [chi] (and ρ [rho]) as a secret symbol for “Christ”. The form of this letter χ itself is giving an inspiration of how Jesus Christ can be illustrated without writing his name out.
The upper area of χ represents the heavenly realm of God, who is the source of living, the light of the world, whereas the lower area shows the creatures who lost the connection to their creator. Therefore, it is dark. Humans are chasing material pleasure.
Yet, there is a way that God prepared for us to turn back to him because He loves us. At the meeting point of those two triangles, there stands Jesus Christ on the cross.
“For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.” - John 3:16