As Stavrianos(1971) suggested in Global History, the first step for human to be different with animal were speaking language, using tools and fire.Language is a tool for human to communicate with each others.
"It seems a miracle that young children easily learn the language of any environment into which they were born. The generative approach to grammar, pioneered by Chomsky, argues that this is only explicable if certain deep, universal features of this competence are innate characteristics of the human brain. Biologically speaking, this hypothesis of an inheritable capability to learn any language means that it must somehow be encoded in the DNA of our chromosomes. Should this hypothesis one day be verified, then lingusitics would become a branch of biology."
----- Niels K. Jerne
'The Generative Grammar of the Immune System', Nobel Lecture, 8 Dec 1984. In Nobel Lectures: Physiology or Medicine 1981-1990 (1993), 223.
There are many people agreed that language is not just a tool for human to communicate, but also a strong bound of a culture, "Bahasa Jiwa Bangsa"(language is soul of a race) is Malay proverb, it bound with a set of technology, culture, tradition, civilization and so on, hence, language is really important.
It is important to learn another language as the first step if you want to know others culture. However, we should not forget that language is a tool for people to communicate, it would be a burden for people to study a new language if he do not necessarily use it.