When the early Church celebrated the Eucharist, it certainly considered itself to be doing more than preaching and singing.

Q. 873. When did Christ institute the Holy Eucharist? A. Christ instituted the Holy Eucharist at the Last Supper, the night before He died. Q. 874. Who were present when our Lord instituted the ...

Q. 897. How are we united to Jesus Christ in the Holy Eucharist? A. We are united to Jesus Christ in the Holy Eucharist by means of Holy Communion. Q. 898. What is Holy Communion? A. Holy ...

It commemorates the Last Supper, when Jesus Christ consecrated bread and wine, instituting the Eucharist in the Christian faith, according to the United States Conference of Catholic Bishops.