One of the most popular Asian classics for roughly two thousand years, the Vimalakirti Sutra stands out among the sacred texts of Mahayana Buddhism [because unlike] most sutras, its central figure is not a Buddha but a wealthy townsman, who, in his mastery of doctrine and ... practice, epitomizes the ideal lay [practitioner]. For this reason, the sutra has held particular significance for men and women of the laity in Buddhist countries of Asia, assuring them that they can reach levels of spiritual attainment fully comparable to those accessible to monks and nuns of the monastic order.
http://cup.columbia.edu/book/the-vim.../9780231106566
...
Some other facts from various sources: The Vimalakīrti Sūtra (sometimes called the Vimalakīrti Nirdeśa Sūtra, or "The Sutra of Vimalakirti's Instructions") teaches, among other subjects, about the meaning of nondualism, the nature of emptiness (śūnyatā) the true body of the Buddha, the Mahāyāna perspective that the appearances of the world are as illusions, all as voiced by the upāsaka (lay practitioner) Vimalakīrti who guides both lay and ordained, including even various mythological Deities, famous Arhats (those who already have achieved nirvana in early Buddhism) and the Highest Bodhisattvas. He does so while lying in his sick bed, although this is actually just a ploy (expedient means) to gather visitors who have come to wish him well and inquire about his health, wherein he lectures about true health which is more than just the body. Vimalakīrti, as a lay figure active in family, social and business life, explains how a Bodhisattva is able to function in the world, engaging in life fully, even to the point of partaking of its pleasures, passions, and defilements [with wisdom, avoiding excess and harm], without being overly attached to them, imprisoned by them, or ultimately corrupted by them. The text has been especially cherished in the Zen world.
https://www.britannica.com/topic/Vimalakirti-Sutra
https://en.wikipedia.org/wiki/Vimalakirti_Sutra