Why did Amenhotep decide to change Egypt's worship of many gods to the worship of one god Aton?

Answer 1

We don't know as much about the "Heretic King" as we would like; subsequent kings and the leaders of several priesthoods did their best to wipe his record from history. He was an odd man from what we can observe, and may have been a mystic or visionary. He certainly was not politically gifted, although he may have been motivated at least in part by the desire to weaken the many strong cult priesthoods of his day, and consolidate the kingdom under his kingship and under his authority as Aten's one High Priest. Kingly authority in Egypt was waning as the various cults of several gods were growing in strength and influence. Whatever his motivations, he surely made many, many powerful enemies, and his Aten cult did not long survive his reign.

for this question there are two strong possibilities worth thinking about. One of them was Joseph the prophet and his guidance which caused Amonhotep to change religion and even his name to AtenAkhen. (Sun (Lonly God) Worshiper). The second idealogoy (extracted from "Sinohe, the doctor of Pharon" book), is that he, somedays before becoming king saw the light in sky and thought alot about gods, and understood that the reason the socities can not prosper is mainly this believing in gods, so as soon as he got king, he stablished the new religion and tried very hard to stop the power of temple (AMON the god), but generally he wasn't sucessful.

Amenhotep IV, more commonly known as Akhenaten, wanted to diminish the power of the priests of Amun. The common people could only worship Aton via worshipping the King. This gave him control over all areas of Egyptian life.

It is not a universally agreed upon fact, but many scholars believe that the existence of Israelite background in Egypt probably influenced Amenhotep, since they were the only monotheistic nation at the time, and had lived in Egypt as slaves for 400 years prior to the Exodus.

Amenhotep IV changed Egypt's religion into a monotheism, or more accurately a henotheism, devoted to the worship of Aten. He essentially merged the cults of Ra and Aten. He changed his name to Akhenaten ("Spirit of Aten") in devotion to his god 5 years into his reign.

We have no historical text explaining his reasons for doing this and any explanation for it would therefore be pure speculation.

Alternate speculations based on known history of the priesthoods:

We know from the one god reference that you refer to Amenhotep IV. He was possibly a mystic and genuinely interested in religion. He may have been motivated by what he thought were basic theological truths. He was not known as a great leader and he wasn't inclined toward military strength, but it is possible that he was also motivated by the desire to consolidate power. In his day, there were many priesthoods, each devoted to a different god or group of gods. The high priests of these priesthoods gained tremendous political and financial power and influence over the previous centuries. By right the pharaoh was the high priest of every priesthood, but there were so many that this part of pharaoh's influence eventually eroded, and many of the high priests considered themselves equal to pharaoh, as indicated by many surviving inscriptions. So it is possible that Amenhotep/Akhenaten devised his religion in order to effectively subvert all of the power of the various cults throughout the land. If he had been a brilliant military man, he might have pulled it off and ushered in a new golden age of pharaonic greatness.