I learned to speak Spanish fluently a couple of years ago (Live or die instant immersion), and while it played with my perception a little bit by opening new ways of expressing things, it didn't really affect how I perceived reality in general. In the least, it wasn't earth-shaking enough to be noticeable.
I think someone who had zero linguistic ability would still be able to think abstractly, because we still have the ability to imagine things that happen. One thing that I've noticed after learning Spanish is that my mind gears more towards images than words, but that may just be me in the first place, or it may be that I have two ways I can express things so I just go the route of using neither.
Really, the only thing that we can't do without language is interact with each other. We can do math just fine without language (Through imagery), and even philosophical stuff is possible to think of through images or emotions. The only thing we wouldn't be able to do is tell each other the cool things we've thought of, since everything would essentially have to emerge from our own minds. Everything exists regardless of whether or not there's a word for it, but because of the human need to quantify everything and express it, and the continued discovery of so much different stuff and so many ways of thinking, language has become incredibly complicated and perhaps even a crutch to original thinking.
So, basically, someone wanted to tell someone about the cool idea about thinking, therefore being, to his friend, so he invented language so his friend could think about it too. After that, people started talking more than thinking, queue modern era.