|The Church as the body of Christ.|
"Our Lord Jesus Christ, before his crucifixion, prayed to His heavenly Father asking that His disciples be one, just as He and His Father are one (John 17:20-23). This is the prayer of all true Christians. It is for this reason that we confess in our Creed that we believe “in One Holy Catholic and Apostolic Church” in which we are saved."
"If a Roman Catholic from France or Italy visits this unidentified church and sees that the Roman rite is seemingly in progress, they would not unnaturally assume that the church was a Roman Catholic Church, in communion with the Holy Father, wouldn’t they? But they would be mistaken. Such a church uses the Roman Missal, but is not a Roman Catholic church, and is not authorised to use the Roman Missal by the Bishop of the diocese (the Catholic bishop, I mean; the Anglican bishop has also forbidden it). Moreover the persons attempting to celebrate Mass are not recognised as priests by the Roman Catholic Church. In short, the visitor from France or Italy may see what looks like the Mass, but what is in fact not the Mass."
* Read an Anglican priest's experience on Fr Mervyn's Blog here.