You're thinking of sin and punishment in an entirely nominalistic/voluntaristic/legalistic way, as if it has nothing to do with the corruption of our nature. Adam's sin corrupted his nature, and he passed that corrupted nature on to his descendants. That is why children die even before they have ever committed a sin. That is why children are now [by secondary nature] disposed/inclined to sin from their infancy.
And you didn't answer my question. Why do you think they are right? What makes their opinion better than anyone else's? They were fallible men, how do you know they didn't make a mistake?
Christ promised to guide His Church into all truth. This is why we trust the Apostles, the writings of the Apostles, the bishops ordained by the Apostles, those in succesion from them, and decisions of such bishops when, for example, they selected the canon of the New Testament. If you don't trust the bishops or the Apostles, then you would know nothing about Christ and the gospel. The authority and trustworthiness of the Apostles and bishops is itself part of the gospel.
-A8
"Adam's sin corrupted his nature, and he passed that corrupted nature on to his descendants. That is why children die even before they have ever committed a sin. That is why children are now [by secondary nature] disposed/inclined to sin from their infancy."
I think we have differnt ideas of what corruption Adam passed on to us. He made us physcial corrupt in that we are mortal, but the resurection is a free gift to all. He passed on a weakness of spirit that will lead us to commit sin eventually.
It is not a sin to be weak or to be mortal, it is a sin to give in to your weakness by committing sin. That child who dies before they are capable of sinning is clean of sin in the eyes of God.
"This is why we trust the Apostles, the writings of the Apostles, the bishops ordained by the Apostles, those in succesion from them,"
Succession was broken. Bishops don't have the authortiy to ordain someone else a bishop so a generation after the apostles were gone you have no more valid bishops. Also, if a person succeeds a king, they are a king, if they succeed a president, they are a president, and if they succeed an apostle, they are an apostle. The pope is not, and does not claim to be an apostle, he claims to be the Bishop of Rome.
This apostacy was predicted in the scriptures:
Amos 8:
11 Behold, the days come, saith the Lord GOD, that I will send a famine in the land, not a famine of bread, nor a thirst for water, but of hearing the words of the LORD:
12 And they shall wander from sea to sea, and from the north even to the east, they shall run to and fro to seek the word of the LORD, and shall not find it.
2 Thes. 2: 3
Let no man deceive you by any means: for that day shall not come, except there come a falling away first,
Rev. 13: 7
And it was given unto him to make war with the saints, and to overcome them:
And many men have looked back at early Christian history and seen how the church fell into apostacy as foretold:
"It does not appear that these extraordinary gifts of the Holy Spirit were common in the church for more than two or three centuries. We seldom hear of them after that fatal period when the emperor Constantine called himself a Christian, and from a vain imagination of promoting the Christian cause thereby, heaped riches and power and honor upon Christians in general, but in particular upon the Christian clergy. From this time they almost totally ceased; very few instances of the kind were found. The cause of this was not as has been supposed because there was no more occasion for them because all the world was become Christians. This is a miserable mistake; not a twentieth part of it was then nominally Christian. The real cause of it was the love of many, almost all Christians, so called, was waxed cold. The Christians had no more of the Spirit of Christ than the other heathens. The Son of Man, when he came to examine His Church, could hardly find faith upon the earth. This was the real cause why the extraordinary gifts of the Holy Ghost were no longer to be found in the Christian Church because the Christians were turned heathens again, and only had earth a dead form left." (Wesley's Works, vol. 7, 89:26, 27)
Roger Williams, pastor of the oldest Baptist Church in America at Providence, Rhode Island, refused to continue as pastor on the grounds that, "There is no regularly-constituted church on earth, nor any person authorized to administer any Church ordinance: nor can there be, until new apostles are sent by the great Head of the Church, for whose coming I am seeking." (Picturesque America, or the Land We Live In, ed. William Cullen Bryant, New York: D. Appleton and Co., 1872, vol. 1, p. 502.)
What was Christian orthodoxy in the 1st centry was declared heresy by these councils of men in the 3rd and 4th century. Not to worry though, neither the death of Christ, nor the apostacy that followed tha apostolic age will prevent Christ and his gospel from prevailing.
I think you can see that I'm not going to be changing my mind on this.