I saw your “Satan Knows the Right Address” Thread and read it, but obviously could not comment on it, because I am non-Catholic. So let me say it here, it is a very interesting read, especially because it has withstood eleven years since it was first published.
The concept has withstood 2000 years. If the Church were only a man made institution, there’s just no way if could have persevered this long. Look at mainstream protestantism. In another generation or two, it will cease to exist, after only 500 years. The conclusions one can draw are obvious.