It seems that the verse "let a man examine himself" guides the views of those who hold to open communion. That is, that it's not up to the church to decide who takes communion; it's up to the individual. And, believers are not to pass judgment in any way over eligibility to partake. Take that to its logical extension and you'll arrive at the view that even if we know someone is an unbeliever, pass the plate to him anyway.
Yet, in a number of scriptures, believers are admonished to pass judgment and to act on that judgment.
For instance, Paul wrote an entire letter to the congregation at Corinth, raking them over the coals and correcting them.
In 5:11 of his first letter, Paul wrote:
But now I have written you not to keep company, if any man that is called a brother be a fornicator, or covetous, or an idolator, or a railer, or a drunkard, or an extortioner. With such an one, no not to eat.]
Some church members, huh?
Paul was basically ordering members to judge other members, and not to fellowship with them. Since the Lord's Supper was usually observed in conjunction with a fellowship meal, the effect was to deny the offenders communion.
In 6:3, Paul demanded that members of FBC Corinth pass judgment.
Do you not know that we will judge angels? How much more the things of this life?
Paul wrote FBC Corinth in Chapter eleven "When you are come together in the church..."
It's clear to me that he meant for the Lord's Supper to be served as a body. Paul goes on to criticize some who mixed the fellowship meal into the Lord's Supper, and in particular those who got drunk, and others who gorged themselves. They were doing it all wrong, and Paul warned them that they were on dangerous ground. Do it right, or God might just kill you. It's that serious.
In Chapter 5, Paul lambasted the church over its treatment of a man who was having sex with his father's wife. Fornication at best, incest at worst. in 5:7 he writes, "kick him out." Oops, there goes Paul, judging again.
I fear that in some churches, this man would still be invited to partake by simply claiming to be saved and a church member.
Oh, and one more thing: wasn't the Passover closed to all but Jews?