His greatest work is the Bijak, or Seedling, an idea of the fundamental one. This collection of poems demonstrates Kabir's own universal view of spirituality. His vocabulary is constantly full of ideas regarding Brahman and Hindu ideas of karma and reincarnation, and yet he also espouses ideas that are clearly Sufi as well as Hindu Bhakti understandings of God. His Hindi was a very vernacular, straightforward kind, much like his philosophies. He often advocated leaving aside the Qur'an and Vedas and to simply follow Sahaj path, or the Simple/Natural Way to oneness in God. He believed in the Vedantic concepts of atman and yet spurned the orthodox Hindu societal caste system and worship of statues, thus showing clear belief in both bhakti and sufi ideas. The major part of Kabir's work as a Sikh Bhagat was collected by the first Sikh guru, Guru Nanak, and is published in the holy Sikh book "Guru Granth Sahib".
While many ideas reign as to who his living influences were, the only Guru of whom he ever spoke was Ramananda, a Vaishnav saint whom Kabir claimed to have taken initiation from in the form of the "Rama" mantra.
His poems resonate with praise for the true guru who reveals the divine through direct experience, and denounced more usual ways of attempting god-union such as chanting, austerities etc. His verses, which being illiterate he never expressed in writing, often began with some strongly worded insult to get the attention of passers-by. Kabir has enjoyed a revival of popularity over the past half century as arguably the most acceptable and understandable of the medieval Indian 'sants', with an especial influence over modern spiritual traditions such as that of Rhadasoami. Prem Rawat ('Maharaji') also refers frequently to Kabir's songs and poems as the embodiment of deep wisdom.
It is a fruitless endeavor, indeed one that Kabir himself disliked, to classify him as Hindu or Muslim, Sufi or Bhakta. The legends surrounding his lifetime attest to his strong aversion to communalism.
In fact, Kabir always insisted on the concept of Koi bole Ram Ram Koi Khudai..., which means that someone may chant the Hindu name of God and someone may chant the Muslim name of God, but God is the one who made the whole world.
His birth and death are surrounded by legends. He grew up in a Muslim weaver family, but some say he was really son of a Brahmin widow who was adopted by a childless couple. When he died, his Hindu and Muslim followers started fighting about the last rites. The legend is that when they lifted the cloth covering his body, they found flowers instead. The Muslim followers buried their half and the Hindu cremated their half. In Maghar, his tomb and samadhi still stand side by side. Another legend surrounding Kabir is that shortly before death he bathed in both Ganga and Karmnasha to wash away both his good deeds and his sins.