The Church teaches that there is a difference between actual grace and sanctifying grace. An easy way to understand actual grace is to remember that it enables us to act. It is the strength that God gives us to act according to his will. Sanctifying grace is a state in which God allows us to share in his life and love. When we speak of being in the state of grace, we mean the state of sanctifying grace. There is no mortal sin in us. This grace comes to us first in baptism and then in the other sacraments.
The graces we receive at Christmas are actual graces that enable us to celebrate the birth of Jesus in a way that is pleasing to God.