Kabir

Kabir Ji was a Sufi Muslim Mystic who shared the ideal of seeing all of humanity as one. His writings are also enshrined in the Guru Granth Sahib, as well as writings of other Sikh, Muslim and Hindu mystics who believed that God is one, only known by different names and paths to the perceiver.

The idea that Nanak Dev Ji inspired him is inaccurate. Rather, a revelation occurred to him when he disappeared for 3 days while bathing in a river, where he received a direct order from God.