You probably think this blog is about you. Sorry, not really. I don't know.
Many Evangelical as well as Calvinist folk are so offended with the closed communion practise of Lutherans. At first, in my mind, that was a concern in me too. It seems so tribal, divisive, clannish and not Christianly at all.
Over at Reformed Catholicism this is being discussed. It was started off from The Pirate with a nice help from Confessing Evangelical . These guys' contributions have been insightful.
To my Calvinist and Evangelical friends who are quite disappointed at the close communion practices of orthodox Lutherans, I have a suggestion, a sincere advice. Do not start with the question "why do they do close communion"? This is not the first question to ask. The first issue is this, "what is happening at the Lord's Supper"? Is this the body and blood of Christ? This is the first question to understand, and when it is settled, the idea of closed communion, you will find is not strange at all.
If you answer that question with a "yes", to which a Lutheran will say also "amen", then you got your answer too - you will see that it makes sense why they practice close communion and they only offer it to those who can say "yes", this is the body and blood of the Lord according to his Word.
If your answer is "no", then why blame them for being closed? This is something to be happy about, why commune at the table to which you can not agree? You should not be desiring it. Besides, this answer means there is nothing special about communion and it is no different (really, I mean no dis-respect) to eating bread for breakfast or taking a sip of wine during dinner.
So the Lutheran practise of closed communion is a very simple issue to resolve. It is not hard and you will not be offended once you know the answer to "what is on the table". Believe me, I was like that too, close communion became the least of my concerns after I got the answer to the question from Scripture (1 Cor 10:16).
Now would an RC commune in a Lutheran table? Of course they won't! I got my suspicions why they won't, I just want to know if they match their reasons.