The commemoration of the Holy Cross has its roots in Constantine’s mother Helena directing an excavation of Jerusalem in the 4th Century where a piece of the “true cross” was reportedly found.
I don’t know if that was really the cross Jesus died on or not. I have been to other significant places of Jesus’ life of similarly uncertain authenticity. What I experienced in those places was not uncertainty about the “truth” but awe at the faith it takes to maintain them for centuries and awe at the centuries of pilgrims to those sites before me.
Each time we make the sign of the cross, may we remember our baptism into the life, death, and resurrection of Christ.