Sean,
Yes, ignorance is sin. But if ignorance alone were a disqualification, no one could partake, "as if the Supper were for those who might be free from sin. Rather, we who are invited to the Supper, com[e] as guilty and polluted sinners." Therefore, as pertains to the Standard's use of "ignorant persons," we need to confine that description to the appropriate designees. And the Baptist, qua baptism, doesn't qualify.
The implication about other points of "doctrinal ignorance" is directly germane to the question, because you claim that error
on the point of baptism is disqualifying. If you do not disqualify
a visitor to your church on the basis of other errors, for example
dispensationalism, its important that you explain just what it is about a baptismal stance that mandates a bar, relative to other errors.
You are simply wrong about our testimony on baptism being "nullified" by admitting a visiting Baptist to the Table. Their children won't be participating in the Lord's Supper, and neither will mine. Their children won't be invited because they aren't even members of any church; mine ARE.
Your comment implies that anyone who is a member in ANY church is subject to the SAME conduct of discipline
in our congregation as are our own membership. But this is simply not true. I will impose discipline on your children, who come over and play at my house under my supervision for several hours--BUT, I will NOT do so in
exactly the same way as I will with my own. I will not proceed to severe consequence with the same dispatch as I might with my own child. Why? because I do not know your child, or what rules-of-the-game he has learned to operate under. I will refrain from telling you (unasked) how to do business in your own house, even if I think you are dropping-the-ball. I should tell you if I gave your kid a "time-out" for the last 3-hours, and isolated him for egregious misconduct, and let you deal with it as you see fit.
The point is, I don't treat your child and mine in the same way at my house, even though I keep the same STANDARDS for your children and mine under my roof. And the reason is patent--
your child isn't MINE. It seems like you would predicate your treatment of all people who come into your church as though they were subject to the immediate expectations of house-members. Surely, there are conceptual/conceivable differences between
1) our members (who are already bifurcated into communicants and non-communicants);
2) communicant members of churches with which we share confessional affinity;
3) members of churches that preach the gospel;
4) members of churches that do not have a pure gospel commitment;
5) not-members anyplace;
and perhaps some other divisions.
Your position is built on the principle that there is NO legitimate difference in how you APPLY the Standards, given a variety of initial conditions.
Consider your freemason/PCA example. First, you said that in the case of your member who became a Mason, you would immediately (!) suspend him from the Table. Really? Would you even give him a chance to resign first? Would you take the time to open his eyes to the mistake he made? How many of our membership even know that the OPC or RPCNA has ever judged these two organizations (the Church and Masonry) incompatible? Wouldn't this require a
time commitment to deal with his blindness? Of course, the answer to that last question is "yes."
The fact that a PCAer might not be under discipline in his home church for being a Mason (which is probably not a fact that I am aware of), doesn't make me responsible for his "undisciplined" situation--no more than I'm responsible as a parent for the fact that your child may be "undisciplined" in an area I think he should be; I don't expect him to take my last-name, in order for me to treat him as cordially as one of my own. I indeed shall hold my children to the strict-standards of conduct which they know, and ostensibly agree to. But I'm going to grant (in advance) your family has standards that are close enough to mine for recognition.
If visitors belong to a real, recognizable church--it has the MARKS of the church! even if imperfectly--other than trying to tell if they know what it means to be a Christian, and learning what their disciplinary status is, I am NOT going to ask them whether they eat/refuse-to-eat "meat sacrificed to idols," belong to the Masons, deny the third use of the law, believe in a literal millennium, or would refuse to baptize their children
if they belonged to a church that expected them to.
I'm sorry, but I do not see Baptist-visitor folk as
in any way able to impose discipline on the Table in this church, much less subject it to the standards of their own church. They are
submitting to discipline, for the moment, through this church and its officers. THEY are the ones giving up their separatist convictions, by receiving Communion at the hands of the "unbaptized," the Word from the lips of an unbaptized preacher, submitting to a man who couldn't even be a member in a Baptist church. I'm willing to let Christ be their Judge, if their "crossed-fingers" is blameworthy.