I have metaphored 'Literature' as 'Space' due to the striking similarities and oneness in terms of existence and characterics as well of both being natural, eternal, and unfathomable phenomena. As sir William Blake has also versed the glory of the existence in his renowned poem 'Auguries of Innocence' :
"To see a World in a Grain of Sand
And a Heaven in a Wild Flower
Hold Infinity in the palm of your hand
And Eternity in an hour"
Space being one such phenomenon has some perceivable aspects which are interrelated to 'Literature' as well. The vastness, depth, mystery, appealing awe, and the irrefutable cruciality in terms of life and life-standards.
As we talk about making life happen in this nothingness, space has the most important role to play, so is the role of Literature amongst humans since it initial versions in form of oral tradition and most recently in form of radio, television, audiobook, and web-series from ancient to the prevalent times.
As long as there is a human-brain, there is going to be the need of entertainment and a search of meaning to whatsoever it comes into contact with and experiences; there comes the role of Literature as being sole medium to the mundane human's myriad mental needs consisting of entertainment, morality of superficial understanding, illogical mental ramblings, psychopathic traumas and an anxiety to express them through the medium of oral and written literature - all such and much will be considered Literature of that particular demarcated time and age.