Humans

Because humans have an impressive capacity for thinking imagining and acting to shape our world. The Upnishads felt there must be a link between the energy of human beings and that of the universe, behind our world of distinct and separate objects, there must be a fundamental unity.

The Gita offers multiple paths by which one can fulfill this purpose of life, through meditation or knowledge or selfless action ( about which we have just been thinking) or devotion and love.