I think everyone would agree with you, but I think it's because these are mostly platitudes. I mean, everyone - no matter their religion - would say their religion is true and I think Scripture is true. But to say the bible is
unchanging is simply not true. It has changed. To say we don't need anyone with any kind of scriptural or pastoral authority to teach us except for the Holy Spirit (and I know you didn't say this explicitly, but other have suggested it) is nuts. Of course we need learned guidance.
To say it's unchanged, I trust you already know that the gospel of Mark (largely agreed as the first gospel by a hundred years and written while some original witnesses were alive) was changed. It ended at 16:8. 16:9 through 20 INCLUDING DIRECT QUOTES BY CHRIST were added. They were added later to help assimilate the narratives of Matthew Luke and John. It was just made up.
Can you read Hebrew? Greek? Latin? You're trusting priests and ministers - and politicians - who were part of the King James council to interpret the Latin scripture to English. You're trusting others to interpret the Aramic to Greek or the Greek to Latin. I mean, I'm not saying the interpretation was wrong or uninspired- only that experts in languages did this and that it is still exegesis. It's still interpretation of what we consider to be truth and in some cases, an interpretation sparked by argument from a council and settled upon by James, a politician, himself.
Fortunately, imho, there are a number of unfaltering truths that have not been mismanaged over the years of scriptural history, however I am always open to interpretation, especially by learned experts with reasons "why" and "how" backed by scriptural language exegesis. Not so much by folks who claim to be led by the Holy Spirit. What the heck does that even mean? It's possible I guess, but I don't think the Holy Spirit speaks to one in one way and another in another. Especially as much as even the bible discussion page here suggests.
Take the verses of John 20:20-23 for instance. Many claim that Priests don't have the authority to remit sin. I read in 23 that Jesus specifically gave the authority to forgive sin to his apostles. We can argue that these verses mean that Christ was talking to His original apostles and that Christ didn't mean that this authority would extend to future apostles beyond them, but the Bible doesn't say that. You can call the Catholic a heretic for believing their Priest - their apostle to Christ - has the authority but you have no "scriptural truth" to back that with. This is just one example of probably many examples of how interpretations can, I guess, cloud the water. Basically I'm not sure if truth is so much relative as it is conditional.