Cardinal Timothy Dolan recently sent a letter to Catholic New Yorkers urging that they return to Sunday Mass “now that vaccination rates are up, Covid-19 restrictions have been lifted, and people are returning to a more normal way of living.”  The Catechism of the Catholic Church explains that “the Sunday celebration of the Lord's Day and his Eucharist is at the heart of the Church's life.” It adds that because “the Sunday Eucharist is the foundation and confirmation of all Christian practice,” participation in Sunday Mass is a serious moral obligation.