Sacraments are visible signs of an invisible reality. The bread and wine used in the Eucharist become the visible signs of Jesus’ Body and Blood, given up for us. The water poured over our heads at baptism is a visible sign that God has cleansed us of our sins. Whether we are talking about confirmation, matrimony, confession or any of the other sacraments, they all work in this way. They are all visible signs of grace given by God.