What I wrote was:
“I don’t believe that the church came to an end within a century of its founding, but I do believe that from its earliest days error would creep in and need to be corrected, and that with the death of the last apostle the only corrective we have is the scriptures.”
I also wrote:
“My opinion is that the differences between denominations are not terribly important. . . A church that preaches the gospel is a “true” church, and its adherents will be saved. As Loraine Boettner put it, “all who accept Christ as their personal Saviour, all who obey and worship Him as Lord and Master, will be saved, regardless of what church they belong to.” I don’t believe in a Great Apostasy, despite error and differences in belief, because I believe the gospel has continued to be preached and that sinners have continued to be saved.”
That error was creeping into the church even from its earliest days is well attested to by scripture itself, and much in the New Testament was written to combat error. The Mormon articles I referred you to do a good job of pointing some of those out, so I see no need to paste them all here. Here are some links:
lds.org/ensign/1988/10/whither-the-early-church
lds.org/ensign/1984/12/early-signs-of-the-apostasy
lds.org/ensign/1995/05/apostasy-and-restoration
lds.org/ensign/1993/11/from-the-beginning
That error continues to this day is well attested to by the various and contradictory doctrines taught by Eastern Orthodox, Oriental Orthodox, Roman Catholic, various Protestant denominations, and what some consider non-Christian sects such as Mormons, Jehovah’s Witnesses, and more. I don’t claim to know which of the competing doctrinal positions are true, if any, and which aren’t, but am content to believe, with Mormon Apostle Dallin Oaks, that “most religious leaders and followers are sincere believers who love God and understand and serve him to the best of their abilities.”
I believe that the scriptures are my only guide to the truth, and that their light on the truth is not so exacting that I can discern whether infant baptism is or isn’t proper, whether Arminius or Calvin was right about predestination, whether Luther or Zwingli was right about the presence of Christ in the elements of the Lord’s Supper, whether Mary was ever-virgin or not, and many other similar disputes. I accept the common Protestant declaration that, “Holy Scripture containeth all things necessary to salvation: so that whatsoever is not read therein, nor may be proved thereby, is not to be required of any man, that it should be believed as an article of the Faith, or be thought requisite or necessary to salvation.” So what I can’t know with certainty from scripture is not something I’m going to call someone a heretic over, even if it is fun to dialogue with others on their points of view on these things. What I think we can all agree on, even some of those you call non-Christian, is that:
“We are accountable to the God who created us. We have sinned against that God and will be judged. But God has acted in Jesus Christ to save us, and we take hold of that salvation by repentance from sin and faith in Jesus.”
whatisthegospel.org.uk/gospelbasics.html