I came across this definition of grace as I read the latest article by my favorite Christian writer, Frederica Mathewes-Green, who is Eastern Orthodox. The entire article, which concerns how men view and respond to church, can be read here.
This definition was written by a priest whom she interviewed for the above article:
"Grace is not just a static concept, as in the old acronym, 'God's Riches at Christ's Expense.' Grace is God's activity in the world and within us, and we're supposed to share in it and participate in it."