For this reason, whoever eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of the body and blood of the Lord. A person should examine himself first, and in this way let him eat the bread and drink of the cup. For the one who eats and drinks without careful regard for the body eats and drinks judgment against himself. That is why many of you are weak and sick, and quite a few are dead. But if we examined ourselves, we would not be judged. But when we are judged by the Lord, we are disciplined so that we may not be condemned with the world. (NET Bible)
This is probably one of those passages that Quakers hurry past, especially with the blood drinking and all, but I think deep down, there is some relation to our practice. I think the key to looking at this section is in the word "judgment". Most of the time, we hear "judgment" used as one of those "end times" things where all the bad people go to Hell and all. But in this case, "judgment" is used in the present tense, as is the word translated as "are disciplined".
Now, although liberal Quakers don't talk about it much, there is a judging aspect of the inner Light that illuminates some of the dark sections of our soul. It can be a painful process, and I think this is really what Paul is talking about. It isn't that if you do this wrong you are going to Hell, but that if you do it wrong, the Holy Spirit is going to let you know about it. Sometimes we may speak in meeting and afterwards have a squirmy, uneasy feeling that we strayed from our guide. I think this is an aspect of that judgment and it isn't meant as punishment but a correction. It seems that Paul is exhorting us to pay attention and follow the inner promptings of the Spirit - not necessarily in following a ritual, but in everything that we do. And if we act against those promptings, God will let us know.