Another major difference, related to the first, is the height of the content. Opera's libretto's are often simply banal whereas the Mass texts set to music are the highest expressions man has ever uttered! The Word of the Incarnate God!
The upshot is that opera is often more beautiful the less you understand the story line (and even watch the staged acting), whereas with the Mass it is the opposite, the more you get into the reality of the action expressed and offered you are more and more elevated.
All opera lovers should experience the Solemn High Traditional Mass with the Mass settings of some of the great composers, otherwise they will understand nothing of the operatic groping for the perfect artistic form which is found solely in the Artist Himself: Jesus Christ, and the worship thereof. In Christ content and form are perfect. The more you understand the more you feel and the higher your worship becomes.
Jesus Christ Himself is the perfect opera!
