@Di Wu,
Words are tools to express ideas, not ideas themselves.
They are also not the only tools we can use to express ideas, but merely the most efficient tools we have.
As an artist, I use pencil and ink on a regular basis to convey messages and ideas without words. My wife is a musician, and uses a piano to convey emotions without words. Effective tools, but not as efficient as words.
The difference between words and art, is that art is not hindered by language.