The Mass contains two parts: the liturgy of the Word
and
the Liturgy of the Eucharist.
The Liturgy of the Word
is a copy
of the
Jewish synagogue service
of the first century: readings from
Scripture followed by responses
from the congregation often from
the Book of Psalms.
The Liturgy of the Eucharist is a
reenactment of the Last Supper.
A
celebrant does what Christ did:
take
bread and wine and say the
same
words Christ said and then
share the now consecrated
bread and wine with the congregation.