Scholars have offered theories that his religion is not strictly monotheistic although only the Aten was worshipped. .
Monotheism can be defined as "the belief in one omnipresent, omnipotent and omniscient god who is above time and space", (New Kingdom Egypt). According to this book also, Akhenaten was not the first pharaoh to practise monotheism. Although he was more likely to be exposed to the religious beliefs of his father, Amenhotep III, the existence of Akhenaten's god the "Aten" or the "Sun disk," posed many centuries before Akhenaten took to the throne. The Aten was simply depicted as an image of a sun disk that housed the Sun god Ra. Several centuries later, Thutmose IV (Akhenaten's grandfather) was fascinated by the idea of the Aten and was often called "the Sun disk" by his bureaucrats. Amenhotep III was also given a name and was known as "the Dazzling Sun Disk." This is evidence that not only did Akhenaten believe in the Aten and that the monotheistic practise was not only a ritual used by him.
Many can believe that Akhenaten's changes to the religion were unique when in fact he was not the first to use the term the "Aten". Before the 18th Century or prior to Akhenaten's reign, no god of the name "Aten" existed. Although Akhenaten was the first to establish a religion based on monotheism and the belief of one god being the Aten, he was not the first to use the name. Akhenaten's grandfather, Thutmose IV, father Amenhotep III and Ramose all used the term prior to Akhenaten taking the throne. Information about the use of the term Aten can be found in the book Studies in Ancient Egypt, edited by Dianne Hennessey and Jennifer Lawless. Thutmose IV had earlier stated he had fought with the Aten and pushed the idea of making "the foreigners to be like the people, in order to serve the Aten forever," (The Culture of Ancient Egypt published by J.A Wilson).
Ramose also used the term, as he was a steward in the Temple of the Aten but was also a priest of Amun.