Language is a system that consists of the development, acquisition, maintenance and use of complex systems of communication, particularly the human ability to do so; and a language is any specific example of such a system.
Literature, most generically, is any body of written works. More restrictively, literature writing is considered to be an art form, or any single writing deemed to have artistic or intellectual value, often due to deploying language in ways that differ from ordinary usage.
Henry Drummond: Language is a poor enough means of communication. I think we should use all the words we've got. Besides, there are damned few words that anybody understands!
Inherit the Wind (1960 film), Jerome Lawrence and Robert Edwin Lee