By definition, Sacred Text is writing that "is venerated for the worship of a deity." For some, Sacred Text is writing that has been "Divinely inspired." However, in the Harvard Divinity course I took on World Religions, we looked at sacred text as writing that inspires, enlightens and/or encourages the reader. Therefore, poetry, prose and even graffiti can be sacred text. (Remember, the word sacred means "to hold as precious.")
I have come to see there are religious Sacred (with a captial "s") texts: Torah, Bible, Qur'an, Bhagadava Gita, etc. But, I have also come to see other writing, such as poetry, as sacred (with a lower-case "s") texts.
Let me give you an example: Basho, a Japanese poet, who traveled around Japan practicing Zen, writing beautiful haiku. His poems are, when taken at face value, little snapshots of his day and observations, BUT, when read critically from a spiritual viewpoint, hold lovely insights into loving-kindness, hope, and simple joy.
this deep in fall--
still not a butterfly.
This idea of looking at sacred text with a lower-case "s" is not new. Scholars have done this for years, but have kept the idea rather parochial. Today, with the internet opening the world to so many ideas and texts, people around the world are looking at a diverse assortment of writings and finding the sacred.
One surprise for me occurred while studying in the Harvard course. We were exposed to the work of a young artist, eL Seed, who paints calligraffiti using Arabic. (Calligraffiti is the combination of calligraphy and graffiti.) His work is so beautiful that even if you don't know what the words say, it still touches your heart and inspires you.