I recently visited a number of European countries. I found about half the churches (Catholic and Protestant) were either closed or used for other purposes such as exhibits and events. 
Latin and Greek were the major languages of the early church. But living languages evolve and change. The Church cannot be a modern tower of Babel. Italian has replaced Latin in Rome. Ancient Greek has evolved into a modern version.
I doubt Latin will stem the exodus from the church.
The role of religion is to help us develop our consciousness and love to go out into our communities to fulfill the mission of Jesus (Reign of God).