Vernon..
I understand why it's important for any church where communion is celebrated in Jesus' Name to be sure those who are receiving the Body and Blood of Christ (which is, as Bob said, if not physically spiritually His Body and Blood we are confessing and claiming to be partaking of in true faith)..anyway, it's an argument that I'm sure has been abused by many more than only Roman Catholics and might be why it's important also to "know one another" in truth.
When we begin to take so casually what we've been taught, confession of sin is a very big part of what the apostles have taught from the earliest foundations of the Church, and we just glibly receive such a gift as Christ's broken Body and Blood having been shed for us without doing so by truly believing and remembering what it is HE has done to save us..
then I agree it is a good thing to stop a stranger and to question whether or not he knows what it is he is doing.
It should be the responsibility of one who is coming to the table to let others know ahead of time what it is we believe in our hearts concerning the Sacrificial act of Jesus Christ we are "remembering" as we do so to honor HIM in this world openly through our faith.
It may be the reason earliest believers (mostly Jewish at the time) and the believers in Rome were coming together to break bread and drink from a common cup in rememberance of Jesus (often at the same time they were having love feasts and sharing meals together) was that most important way they were confirming their own faith while studying together from God's Word, listening to the teaching of those who had been especially gifted and called to rightly divide the Word of Truth for the sake of the whole body as all members were feeding together on CHRIST HIMSELF..
He is our LIVING HEAD in HEAVEN..
every member, joint and part is supplied by HIM just like our own bodies are here on earth fed through the blood that courses through our veins, pumped by the heart, directed by the brain!
without that nourishment a part will die. Without being rightly connected to the Head and to each other a part ends up without life and is cut off or falls off.
In that sense, the Catholics have it right concerning the importance of feeding on Christ Himself and communion should be for us a sacred act to express our faith as we are constantly "confirming" to each other and to the world around us we are members of the HOLY CHURCH called by the NAME of our HOLY LORD.
It's when we leave out the "HOLY SPIRIT" the church on earth ends up being nothing but another "dead body" ..
Remember what Paul warned about those who were sick and dying for not taking seriously such an "act" as they ran to a table without rightly discerning the Body of Christ..
there were many things Paul and the apostles taught about why it was they did as they did, why we do yet.."lay hands quickly on no man" ..did that mean that the laying on of hands whether it be for the purpose of anointing another with oil to bring healing should be considered a sacred act and that one should be sure before laying on hands that a man has repented from sin?
or was it to do with a minister who was anointed and ordained to teach, evangelize, go out as a missionary into the world with the blessing of
his fellow disciples and apostles?
whatever the case, obviously one thing is certain..in this world much of what we have held sacred has now been subjected to the profane and many who are naming Jesus as "Lord" are blaspheming His Name unless from their hearts they truly are willing to be obedient to His commands.
"DO NOT TAKE HIS NAME in VAIN" is one of the first commandments we've been given. Jesus said it like this..
"Why do you call me Lord, Lord and not DO the things I command?"
He came to fulfill, never to destroy the LAW of our Father in Heaven.
HE also calls what our Father calls GOOD for what it is..and He recognized the evil one and what it is he is out to accomplish as the enemy of the SAME LIVING LORD.