It’s important that you understand a few things. There actually is no such thing as a “Roman Catholic” as that’s sorta a term that was created by Anglicans, who considered themselves “English Catholic.” Generally speaking, the proper term for what you refer to as “Roman Catholic” is really “Latin Catholic;” this is because the Catholic Church is made up of many traditions, of which Latin Catholic is only the one most people in the US are aware of. Others include Ukrainian Catholic, Maronite Catholic, Coptic Catholic, Ruthenian Catholic, Melkite Catholic, Greek Catholic, Syro Malankara Catholic, Chaldean Catholic, etc.
Now, the thing that you have to know about liturgy is that no matter how much it resembles a Catholic Mass or Divine Liturgy, that because Presbyterians do not have clergy with valid Holy Orders and Apostolic Succession, then it doesn’t really matter what a Presbyterian does for his services. The reason is because we as Catholic are forbidden to receive Communion at your churches because we do not believe that your communion is actually Christ’s Body and Blood. This is a MAJOR belief for us; we actually believe that at Mass, the bread and the wine, when consecrated by a validly ordained clergy, actually ceases to be bread and wine but becomes Christ’s actual Body and Blood, and that each Mass or Divine Liturgy is an unbloody re-presentation of Christ’s sacrifice. In other words, we worship and adore the Eucharist because it is actually Christ.
Now, valid ordination is outlined in the Bible. How? A good example would be the ordination of St. Stephan in Acts, how the Apostles laid hands on his head. Acts continues to point out the centrality of laying on of hands, and also that it be performed by someone who can be traced to an Apostle. The bottom line is this: as Catholics, the only (name removed by moderator)ut that we can give you is that what is required for it to be “catholic” is validly ordained clergy with valid Apostolic Succession and a valid Consecration.
