Rights are granted by God, the Constitution merely acknowledges them. If you don’t believe in God, or think human hierarchies determine rights, then they aren’t really rights anymore. They are privileges.

Barring physical limitations, what you can and can't do is ultimately determined by what the society you are by and large a part of deems to be acceptable behaviour.

Government rules and social norms can change over time, it ultimately doesn't matter what you feel is "right" or what some law says is "right", it's really about what you can get away with.

A large part of what you can get away with is determined about whether or not you will ultimately be penalized for your actions (possibly through violence), and laws can keep people aligned on what is or isn't going to be accepted and when people deemed to be acting in a socially unacceptable way are likely to be penalized in some form.

While "rights" may be somewhat philosophical, they can have very real physical "weight" behind them in the form of other people "enforcing" them.

And finally, in case you are mistakenly under the impression that I think it's okay for anyone to do anything they want so long as they can get away with it, I don't, but that discussion drifts into the territory of morality and ethics which, while related, are nevertheless different and very large topics of discussion in themselves.

If you believe rights are what God and the Constitution grant, then they're meaningless. Some piece of paper has no real–world relevance. Cops shooting people in the face has real–world relevance.

God doesn't have a typewriter, as far as I know. When he gets one I hope he clears up which 99.9% of human religions are heretical and which 0.01% are divine law, that would be really helpful.

In the meantime, rights are not granted by anyone. They are a contract between the governed and those that govern. Breaking that contract is the sort of thing that doesn't end up working out well for the governing class.