Answering some back and forth multi quotes: Kathryn’s responses in blue.
“for clarity I think it to be a Christian Church, just not the one true Church.”
For clarity, it is The One Holy Catholic and Apostolic Church.
“well since you asked, here is my opinion: I don’t think that you can draw a clear line as the error is quite varied. There is nothing wrong with the mid 2nd century view of Mary as the new Eve, but there is most certainly something wrong with the elevation of Mary to sinless, co-mediatrix.”
****Thousands of years of Church tradition disagree with the above opinion
“Another example would be the elevation of the bishop to a monarchical position. That seemed to start about the time of Ignatius, but it wasn’t the situation throughout the empire at that time. Ignatius’ insistence on the centrality/necessity of the bishop may have even been a practical and good solution to battle heresy, but to make it the required form of Church governance for all time is just wrong. From there, the situation wrt a ministerial clergy just seemed to get worse (in some regards). The view of the Lord’s Supper went down the wrong path and as a result a priestly caste was needed to officiate (even though the term “priest” is essentially unused in the first two centuries of the Church wrt offices within the church). The more matters one considers, the more complicated the whole issue becomes.”
Read Hebrews: Speaking of Christ Himself: "He is a priest forever, according to the order of Melchizedek (7:1-29)
“If you are determined to have a time specified, then I would say that by the end of the second century the problems are well on their way and by the end of the 4th century they are pronounced (though the problems would continue to grow in size and number…perhaps Vatican II would represent a step back in the right direction). In any event, one could go on and on discussing the introduction of various errors and development of those errors into ever more serious errors, but it is impossible to say when such error achieved a critical mass.”
**And the thousands upon thousands of combined protestant and “New Age” belief systems that do not agree with each other, this is error at a critical mass. **