Do you know someone who may be curious about the Roman Catholic Mass and wants a general explanation of how we Catholics worship? Let me recommend the following text.
First, no one may share the Eucharist with Catholics unless they believe what we teach is true, unless they are washed in the regenerating waters of baptism for the remission of their sins, and unless they live in accordance with the principles given us by Christ. Second, note that we do not consume the Eucharistic bread and wine as if it were ordinary food and drink, for we have been taught that as Jesus Christ our Savior became a man of flesh and blood by the power of the Word of God, so also the food that our flesh and blood assimilates for its nourishment becomes the flesh and blood of the incarnate Jesus by the power of His own words contained in the prayer of thanksgiving (or Eucharistic Prayer). Thirdly, the apostles (in their recollections that we call gospels) handed down to us what Jesus commanded them to do. They tell us that He took bread, gave thanks and said, “Do this in memory of me. This is my body.” In the same way He took the cup, gave thanks and said, “This is my blood.” The Lord gave this command to them alone. Ever since then we have constantly reminded one another of these things.
Next, the rich among us help the poor and we are always united. For all that we receive, we praise the Creator of the universe through his Son Jesus Christ and through the Holy Spirit. Note that we have a common assembly of all our members on Sundays, whether they live in the city or the outlying districts. At that time, the recollections of the apostles or the writings of the prophets are read, as long as there is time. When the reader (or lector) has finished, the presider of the assembly (or priest) speaks to us; he urges everyone to imitate the examples of virtue we have heard in the readings. Then we all stand up together and pray. After that common prayer, bread and wine and water are brought forward. The presider (or priest) offers prayers and gives thanks to God as he is empowered to do, and the people give assent by saying, “Amen.” Thereafter, the Eucharist is distributed, everyone present communicates, and the deacons take it to those who are absent.
Also note that the wealthy, if they wish, may make a contribution, and they themselves decide the amount. The collection is placed in the custody of the presider, who then uses it to help the orphans and widows and all who, for any reason, are in distress, whether because they are sick, in prison, or away from home. In a word, he takes care of all who are in need. Finally, we hold our common assembly on Sunday because it is the first day of the week, the day on which God put darkness and chaos to flight and created the world, and because on that same day our savior Jesus Christ rose from the dead. For he was crucified on Friday and on Sunday he appeared to His apostles and disciples and taught them the things that we have passed on for your consideration.
This text explains the Mass pretty clearly, and it was written before the year 165 by a Greek philosopher and Roman Catholic who died for his Faith, and is known by the name of Justin the Martyr. We’ve pretty much been worshiping that way ever since.