1) "The question is not 'which is the true church?' but 'is God at work in the local church I am at present attending?'. If He is, then it is irrational for a disciple of Jesus to abandon His workshop..."

The problem is, there's no way you as a mortal, fallible being can interpret where God is or isn't at work, not based on external appearances (since there have been a lot of successful cult leaders), and not based on internal feelings either (since the heart is deceptive). In fact, it seems so vague and so open to interpretation that almost anyone could determine "God to be working" in their own congregation. This is one of the problems with the Luther-like "go it alone" approach in general, because a soul can not know these things for sure. Is it the work of God or personal pride or worse, Satan himself whispering in the ear? ...etc. It's better to be able to know for sure and trust in what God has revealed rather than having to rely on one's own judgement of things.

God is also technically "at work" everywhere and in all places, even in the lives of atheists and pedophile communities, but I suppose this "is God at work there" question may be more of a Protestant thing. I grew up as a "couch protestant" watching the various televangelists (never going to church of course), and I do remember what it's like to "take everything they say with a grain of salt" and be actively on the lookout for "wolves in the fold" ... like the "prosperity gospel" and money grabbing schemes or other lies. I'm sure you know what I'm talking about.

The thing is, the same kind of thing exists in Catholicism but they call it "private revelation." Like I said, not everything espoused by a Catholic everywhere, nor everything that the Church has called "worthy of belief" is automatically part of the deposit of faith. This kind of leads into your point about the brown scapular devotion. There's a difference between "public revelation" and "private revelation." Catholics because that public revelation died with the last apostle, just like Protestants. Private revelation is nothing but the ongoing assertion that God is still at work in the world despite the death of the last apostle, but all of it must be taken with a grain of salt. Public revelation is what is mandatory to believe. Private revelation is optional. The brown scapular and ALL that is entails is optional. If it's not your thing, you don't have to believe a word of it. You will find many Catholics who don't, and that's fine, because it's private revelation. So much is optional in Catholicism.

"2) 1 Cor 5 gives an instance of Mt 18 in action - it does not provide a basis for ecumenical councils"

I agree with you and I didn't mean that it provides a basis for eccumenical councils. What it does provide a basis for is Church discipline and the practice of "excommunication." What Paul is suggesting the Corinthians do is excommunicate the member to provoke him to repentance and to avoid scandalizing the Church and the faith by keeping him around, but then when he does later come around, he tells them to restore him fully to communion.

"Now that means that I've fallen away completely from the 'divine and Catholic faith'."

I don't see how this would be a sticking point for protestants, seeing as the very nature of being protestant means that you are "protesting" the Church's authority to begin with. It follows that you would protest what the Church has defined using its authority. My question is why you accept some things the Church has dogmatically defined (like the doctrine on the canon of the NT) and protest others (like the doctrine on the assumption). Furthermore, the Church recognizes grades of Christian unity among all... this is why the Church talks about those in "full communion" and those who have "imperfect communion." It regards protestants as having an imperfect communion. First of all, the Church teaches that people must obey their conscience, so if a Protestant through no fault of his own has a fall out with the Church to such an extent that he is utterly convinced of the "whore of babylon" stuff and his conscience would convict him otherwise, then he's not bound by Church regulation since he's excommunicated himself. Church regulation is only meant for those who are in full communion, and only for those whose consciences would be convicted by it. If you read that statement about the doctrine of the assumption and your conscience isn't convicted by dissenting, then you're not in full communion anyway, so it doesn't apply to you. What they're talking about is how fully-communicated Catholics can't retain their status as being in full communion without accepting the doctrine (because those Catholics would be going against their conscience). Protestants by definition are already not in full communion, but for them it's due to a matter of conscience that they are not in full communion, so it doesn't apply to them.

Look, I'm not the smartest person in the world, nor do I know everything there is to know about canon law, catechesis, and Church history... I'm just trying to be faithful to the Lord like anyone else.

"So by its actions, the Roman Hierarchy proves that it doesn't believe its own 'infallible' statements."

You can't take one statement out of context and use it to nullify other statements the Church has made at higher levels. The same thing happens when unbelievers take quotes out of Leviticus to contradict the statements of Christ. The fact is, the statement you quote isn't meant to include Protestants. Protestants have a different form of communion with the Church from the ordinary full-communicated Catholics that the statement was meant for. The Church likes to look at things positively, and for the sake of Christian unity, likes to focus on points of agreement with Protestants over points of difference, saying that protestants who conscientiously object to the Church operate under a different standard they call "invincible ignorance." It basically means that God's grace is available to all human beings in ways known only to God, and though people's personal consciences may be malformed or improperly influenced through no fault of their own, God is indeed "greater than our hearts" (1st John 3:20). The Church asks that all people of faith inform their consciences if they can, so that they can be set free by the truth, but recognizes that a person is only lost if they know the truth and continue to dissent from it (that is, they act against their conscience). If a person is acting according to their conscience, even if it be malformed, then God is greater than the person's heart.

Basically, if you're a full-communicated Catholic and you know in your heart that the Church was founded by Christ and you dissent to this one doctrine (the assumption), then your conscience convicts you. If you're a protestant and you don't think the Church was founded by Christ and to accept this doctrine would be to go against your conscience, then you're acting in accord with your conscience by not accepting it. The Church says the later is the result of a malformed conscience, but the Church doesn't pass judgement on why that person's conscience is malformed (whether it's really through no fault of his own or not), preferring to leave that up to God to do.

"You have an appalling record of crass errors in the past - yet you ask me to ignore those errors and trust you unconditionally. It's not a matter of arguing when the apostasy occurred; it's that you have done unacceptable things in the past. Given that is the case, you don't get to get special treatment."

Richard Dawkins says the same thing about Christianity in general. In fact, that actually sounds like a Dawkins quote.

"It seems that from God's perspective the local Christians of an area constitute the church. Unfortunately these days we are divided into our denominations..."

If that was indeed the case, I don't see how denominations could be avoided, especially before the was even a canon of scripture, any church documents, or even councils to determine what exactly the deposit of faith was. If it truly was just a ragtag random batch of believers in Christ here and there doing whatever they each saw fit in their geographical locale, then the Church was not of "one mind" ever and Luke's observation was wrong.

But that's not true, as anyone who reads extra-Biblical sources will know, for example. Pope Clement I, at the end of the first century, who had been an associate of Paul (Paul even mentions him among others whose "names are in the book of life" (Philippians 4:3))... later also wrote to the Church in Corinth to settle a dispute there, using his authority to do so, for which they quickly settled as a result. One has to wonder why, if Clement of Rome was just any other "local bishop" why he would intervene in the affairs of the Church in Corinth, and why they would adhere to his authority if they regarded themselves as equal to the seat of Peter? (See "First Epistle of Clement")... I'm not saying it's scripture (although Clement's letters were read in the early Church as though they were scripture), but it's a historical Church document (just as the letters of Paul are) and informative in any case about how the early Church was organized around the preeminence of the bishop of Rome (Peter's seat).

"Or rather you don't unless they are leading you badly astray. If when in fulfilment of the instruction to 'test everything' you discover that the teaching being served up is consistently defective, then you need to reconsider."

Which is exactly why I left protestantism behind to join the Church founded by Christ, for better or worse. I used to be anti-Catholic just like the best of them. I believe they were the "whore of babylon." I spoke venomously about them publicly. I considered they were all idolaters and that I was following the Lord "in spirit and truth" by just doing things "my way" ... or "I don't need all that churchy stuff, because I just have me and Jesus." That was until I found out that Jesus, the guy I claimed to know, actually founded a Church and imposed rituals and disciplines on it that I could no longer ignore and still claim I "knew" the man. I came to a point where God asked me "Who do you say I am?" (Before I had even read a word of scripture), and I mechanically answered back "You are the God of Abraham, Isaac, and Jacob." ... only to realize I didn't know who any of those people were. How could I call my God "the God of so-and-so, so-and-so.." and not even know who those people were? But I figured the OT was all fables and fairytales anyways, so I decided I'd just read the "red letter" stuff, because everything else was the "traditions of men." It turns out that when you read the "red letter" text, Christ makes references to Noah, makes references to Jonah, and talks about Moses and God's work in Israel very often, so I figured I had to find out what the OT was about as well... etc. etc.

Long story short, the more I learned and read, the more the Catholic Church seemed inescapable as all the artificial boundaries that I had set up fell away one by one. Eventually I had to realize that I couldn't have it "my way" anymore, because regardless of what Luther says, it's not about "just me and my Bible"... it's about "God and His Church." If the Church, as Paul says, is "the Body of Christ" (Colossians 1:24), then the Bible itself was telling me that I couldn't afford to make it all about "me and my interpretation" anymore. That's why I became Catholic. That's why I finally got Baptized. That's why I finally started going to Church. If I had stayed "protestant" I would never have done any of that.

"A prophet is one who claims to speak for God... On the whole Rome has a failure rate in prophecy as bad as anyone else; there's no visible evidence of God's special grace."

No evidence apart from the word of Christ Himself who told his apostles: “And surely I am with you always, even to the very end of the age" (Matthew 28:20). The Protestant claim is that at some point Christ reneged on this promise and the Church He founded ended up falling into universal apostasy only to be saved some time later by a guy named Martin Luther and his companions. You could say I've tested Luther (I even thought of becoming Lutheran), but I don't see evidence of special grace in him either, nor in any of the reformers.

Christ wasn't like the Buddha. Christ founded a "Church," not a free-floating philosophy. He appointed Apostles, gave his Apostles specific instructions on rituals and liturgy to be practiced everywhere, and made them make non-negotiable commitments to make disciples of all nations by the means that he was instituting through the organizational structure. He also promised to guide the decisions of the organization going forward through His Holy Spirit, promising never to leave them orphans. None of this sounds like he was just giving forward some kind of free-form philosophy that some "amorphous collection of believers" could distill for themselves here and there as they felt like it. Everything he did was essentially to set up an earthly kingdom with spiritual governance.

As a former anti-Catholic protestant, I don't trust Rome because Rome is Rome, I trust it now because I've come to believe that the Church founded by Christ is actually the Body of Christ. I don't see them as "speaking for God" as much as simply "God speaking" through His creation. As St. Joan of Arc said, "About Jesus Christ and the Church, I simply know they are just one thing, and we shouldn't complicate the matter."

Amen to that.