English-speaking Catholics around the world were taken by surprise during the Mass on Sunday after being accustomed to praying the exact same way for 40 years.
The Mass liturgy, or the text of the most sacred Roman Catholic rite, has been re-launched in the English-speaking world to comply with the Vatican's wish for a more traditional and spiritual tone.
At Saint Monica's church, an impressive neo-Gothic building in New York City, parishioners clearly struggled to adapt to the discreet shifts in language laid out on a neatly printed pamphlet.
For decades, when the priest declared, "The Lord be with you," the congregation would reply: "And also with you." That was so ingrained that although the pamphlet instructed in bold that the response was now, "And with your spirit," few managed to make the switch.
Priests, who have far more to say during Mass and know their parts by heart, were having to tiptoe through the texts.
"It will probably take four weeks for the priests to get used to the rhythm," Monsignor Thomas Modugno told AFP afterwards. "It's easier for the people. It's hard for us priests: you get distracted for a moment and automatically you go back to the old version."
The new wording reflects years of work involving English-majority Catholic communities from the United States to Europe and Africa to Asia.
Changes are frequent, but small, rather than structural. There is nothing on the scale of the revolution brought by the Vatican's abandonment in the 1960s of the centuries-old Latin Mass.
However, church officials say they want to restore some of the linguistic spirit of that old Mass by tweaking the English translation to reflect more accurately the meanings and cadences of the ancient Latin.
The results have been criticized by some Catholics as unnecessarily archaic-sounding and confusing.
The Cleveland.com news site quoted one outspoken bishop, Donald Trautman from Pennsylvania, complaining that the alternations introduce a "jumble of subordinate clauses" that threaten "pastoral disaster."