On the Holy Sacrifice of the Mass

"All Good Works together are not of equal value with the sacrifice of the Mass, because they are the works of men, and the holy Mass is the work of God. Martyrdom is nothing in comparison; it is the sacrifice that man makes of his life to God; the Mass is the sacrifice that God makes to man of His Body and of His Blood. Oh, how great is a priest! if he understood himself he would die. . . . God obeys him; he speaks two words, and Our Lord comes down from Heaven at his voice, and shuts Himself up in a little Host. God looks upon the altar. "That is My well-beloved Son, " He says, "in whom I am well-pleased. " He can refuse nothing to the merits of the offering of this Victim. If we had faith, we should see God hidden in the priest like a light behind a glass, like wine mingled with water. "
Catechism on the Holy Sacrifice of the Mass by St. Jean Vianney