A weakening of faith in God, a rise in selfishness and a drop in the number of people going to Mass in many parts of the world can be traced to Masses that are not reverent and don't follow Church rules, said a Vatican official and a consultant.

"If we err by thinking we are the centre of the liturgy, the Mass will lead to a loss of faith," said Cardinal Raymond Burke, head of the Vatican's supreme court.

Burke spoke March 2 at a book launch in Rome.

The book, published only in Italian, was written by Father Nicola Bux, a consultant to the office in charge of papal liturgies.

The English translation of Bux's book title would be, How to Go to Mass and Not Lose Your Faith.

Burke said he agreed with Bux that "liturgical abuses lead to serious damage to the faith of Catholics."

Unfortunately, he said, too many priests and bishops treat violations of liturgical norms as something that is unimportant when, in fact, they are "serious abuses."