500
In early Christianity, what were the apostolic churches? What does it mean to be “in communion with Rome”? What do we mean when we say that God gave the Catholic Church the “fullness of the means of salvation”? (essay 2)
The apostolic churches are early Christian communities that were founded by one or more of the Apostles. Being in "communion with Rome" means a community recognizes the authority of the Pope and the official teachings of the Church. The Church having the "fullness of the means of salvation" means that the Church possesses all of the spiritual tools that the Christian needs to be holy.