Actually the RCC isn't, especially since it has an almost 2000 year history that traces back to the apostles.
All religions are not static-- they're dynamic, largely because of two reasons: 1.times change so periodic adjustments have to be made, and 2.there are things done in the early church that were not written down in the scriptures or needed to be clarified since they may be too vague. Ideas as to what Jesus was vis-a-vis God is just one sticky-wicky that the Church had to try and deal with. Needless to say, there was much more.
The Church simply is not just made up of the Bible, and it was the CC that actually selected the canon of the Bible that you use.
Yes, religions change. God, and His word do not change.
There is a lot of verses that indicate the truth was being compromised in a major way. Read Paul's letters to the churches as well as those he wrote to Timothy. You'll see that many were infiltrating the Christian church and teaching false doctrine.
The Bible says it contains all things that pertain to life and godliness.
2Pet 1:3,
According as his divine power hath given unto us all things that [pertain] unto life and godliness, through the knowledge of him that hath called us to glory and virtue:
If words have any meaning at all, this verse says that there is no reason to go outside of the scriptures to learn about God. God never mentions Apostolic writings, catechisms, statements of faith, or anything else the RCC inserts into right doctrine, especially when those insertions are contrary to the Bible. For example, the RCC prays to saints while the Bible says that everybody that ever died will stay dead until God raises them from the dead for judgment as per the Book of Revelations. The Bible is quite clear on the status of dead people.
Eccl 9:5,
For the living know that they shall die: but the dead know not any thing, neither have they any more a reward; for the memory of them is forgotten.
Ps 115:17,
The dead praise not the LORD, neither any that go down into silence.
There are others. Just look for them.
There is actually one exception to this rule, and that would be Jesus Christ. He did rise from the dead.
John 3:13,
And no man hath ascended up to heaven, but he that came down from heaven, [even] the Son of man which is in heaven.
Clear as a bell. The Bible says Jesus is the only one who rose from the dead and is not in heaven. So who are all the saints the RCC prays to? They are all dead and not listening. You just have to make up your mind as to who knows best, the Bible or the RCC.