In today's first reading, we see that the concept of exalting a creature on a staff was a way to provide healing. In this case, Moses places a bronze serpent on a staff to heal the Israelites from the venom of the snakes that are plaguing them. All they had to do was gaze upon the staff (and believe) and they were healed.
Jesus's death and Resurrection are saving us from a more vicious snake attack: that of the devil tempting Adam and Eve (and us) to sin, the ultimate venom. By gazing upon Jesus on the cross and believing, that venom is removed from us and our path to eternal life is clear. Jesus makes this comparison between Himself and Moses's serpent staff in today's Gospel reading. This is not a coincidence; it is part of God's greater plan.
As Catholics, the Sign of the Cross is a consistent part of our lives. We say this small prayer before and after our other prayers, as we enter and leave church, and when we are moved to do so in our daily lives. The cross is the sign of our redemption and future resurrection. It affirms our belief in the Holy Trinity. And it shows us that life can be born from death.