Various advocates and critics of panentheism find evidence of incipient or implicit forms of panentheism present in religious thought as early as 1300 BCE. Hartshorne discovers the first indication of panentheistic themes in Ikhnaton (1375–1358 BCE), the Egyptian pharaoh often considered the first monotheist . In his poetic description of the sun god, Ikhnaton avoids both the separation of God from the world that will characterize theism and the identification of God with the world that will characterize pantheism. …Early Vedantic thought, as well as some modern Indian thought, implies panentheism in non-Advaita forms that understand non-dualism as inclusive of differences.
John Culp, in "Panentheism" in The Stanford Encyclopedia of Philosophy (2009).