And for this reason some of you are sickly, some weak, and some of you sleep (are dead). 1Cor.11:30
Was open communion acceptable in Paul's eyes? Certainly not! Because of the abuse of the members of the Church at Corinth God judged them harshly, and killed some of them. Certainly there was a love feast that preceded it, as their custom was. And at that time some got drunk, and were very gluttonous as well. They formed cliques: the rich with the rich and the poor with the poor, so that the poor went home hungry and the rich went home over-fed and drunk.
Paul rebuked them: "What, do you not have houses to eat and drink in!"
And then proceeded with an order and reasons for having the Lord's Supper. It was a solemn and sacred time. It was symbolic not sacramental. It was worshipful but not liturgical. One of the key statements made was "Let a man examine himself." This statement in itself rules out "open communion." There was to be unity in the church. They were to examine themselves as to sin, doctrine, any reason why they should not partake. Was there a reason why they could not partake in the Lord's Supper while in fellowship with that particular group of believers?
Suppose you were at Corinth, and the Lord's Supper was being held. You knew that the Lord had just struck some with serious illnesses, and had even killed others for abusing the Lord's Supper. Would you take the chance that if you could not fellowship with this church on the basis of both faith and practice, and moral living, that you would partake of the elements with them?