text: The Church teaches per the Council of Trent, Session XXII, September 17, 1562 (summarized) as follows:
  1.The Mass is a true and proper sacrifice which is offered to God.
  2.By the words, "Do this in commemoration of me" (Luke 22:19; I Corinthians 11:24), Christ made the apostles priests. Moreover, He decreed that they and other priests should offer His Body and Blood.
  3.The Sacrifice of the Mass is not merely an offering of praise and thanksgiving, or simply a memorial of the sacrifice on the Cross. It is a propitiatory sacrifice which is offered for the living and dead, for the remission of sins and punishment due to sin, as satisfaction for sin and for other necessities.
  4.The Sacrifice of the Mass in no way detracts from the sacrifice which Christ offered on the Cross
  
  Since these are dogmatic pronouncements, all Catholics are bound to give full assent of the will and mind to them.