Nice response Scott
Good post. I guess we agree for the most part on a LOT. 
You are correct on the inclusion of Gentiles. This was a ‘question’ that arose in the very early Church. That is the main reason for the Council of Jeruselem recounted in Acts. After that authoritative council, this issue was resolved.
I think you have been exposed to a lot of Fundamentlist Evangelical brothers in the faith, am I right??? No offence to them, but I have the exact same problems with the logic you speak of.
I was raised with this circular logic, and was totally frustrated by it as a young adult.
The logic you refer to is not taught by any traditional authoritative theological bodies. It is usually ranted on by mis-informed followers.
The basic great divide of Christianity as a Religion vs. some eastern beleifs is that it is a religion of Revelation, not of discovery.
It frankly requires more than blind faith if want to do more than just hope you are right. An understanding of how the Bible became the Bible (Cannonization) and how it functions within the body of the Church is critical I think. Once you seperate the two, you get nothing but radical division in Christianity.
As far as Truth. Your man Paul, says in Romans the first chapter, that this truth is there to be seen by all, even without having an education knowlage of organized religion as you say. He does not say this in totality, but does say it.
I think a lot of this truth is self evident as you point out too. However, in any religion of revelation, the reason for the revelation is to impart truth that may otherwise, be unknown in specific terms. Therefore, the Church believes that there is a combination of the two certainly.
You would find it very intersting what the Catechism of the Catholic Church say reguarding other non-Chirstian religions. You would find more agreement there with your view than you may imagine.
I know this is a huge topic, but each element expands into volumes of information.
Let me say this reguarding your statement that Paul’s interpretations did anything. The Church interprets Paul’s letters, not the other way around. Some bodies focus more on Paul’s letters than others, but that is not the way the traditional church has operated. Any division in the Church is attributed to people interpreting Paul and others letters (The Bible) in different ways. Would that the Apostle Paul were here to put an end to this and tell us what he meant.
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