From Saint Theodore the Studite:
How precious the gift of the Cross. How splendid to contemplate. In the Cross, there is no mingling of good and evil as in the tree of paradise. It is wholly beautiful to behold and good to taste. The fruit of this tree is not death but life, not darkness but light. This tree does not cast us out of paradise, but opens the way for our return.
This was the tree on which Christ, like a king on a chariot, destroyed the devil the lord of death and freed the human race from his tyranny. This was the tree upon which the Lord like a brave warrior wounded in hands, feet and side, healed the wounds of sin that the evil serpent had inflicted on our nature.
A tree once caused our death, but now a tree brings life.