What is the purpose of a bill of rights anyways? To expand government? Or to limit it?

In parts 1 through 4 of this series (Scroll to the bottom for more detail about the parts) I have been examining progressivism and its relation (or lack therof) to the 1803 court ruling Marbury vs Madison.

Here in part 5, I just want to ask two questions. First, what is the purpose of a bill of rights? We could be talking about the Bill of Rights of the Federal Constitution, or the Bill of Rights that exists in your State constitution. It doesn't matter really, where that bill of rights happens to exist.

What is it for: Is it there to expand the power of government and give them more power over jurisdictions which more local than itself? Or is said bill of rights there so that the people know what they should expect, and therefore to limit the power of government?

I'll state it plainly what I believe: I believe that a bill of rights exists for the purpose of setting limits to the government to which it is attached.

My follow up question is this: If a bill of rights, intended to limit government authority, is perverted into becoming an object that expands governmental power, is it no longer a bill of rights for the people? Does it then become a bill of rights for the government? As we come to the conclusion of this series, this is a very important question to cover.

In part 1 of this series, I asked one very simple question: Are progressives telling the truth about Marbury?

In part 2, I examined the gap between the activist cases of the early-mid 1900s and the 1803 ruling.

In part 3, the negative and positive aspects of how the Marbury ruling functioned were examined.

In part 4, the constitutionality of the judiciary act was examined.

Yes, this series is getting rather long, but I assure you it is going somewhere.

https://tinyurl.com/y89d4a5z