Worship of the sun is perhaps the most ancient form of religion. The sun impacts all elements of human life, from the subtle to the obvious. Every part of your existence is a direct consequence of the sun. A world without the sun would be a world without life. A world without plants, animals, humans. There wouldn't even be microscopic bacteria to inhabit earth. Life itself is the sun. Its one of the only constants in human life, and one of the first things people turned to for guidance.

The sun has been a primary deity in every culture on earth, but who or what is the sun, really?

The sun in world religion: Egypt

The Egyptians worshipped the sun in many forms, and their religion evolved over time. Many Egyptian deities were associated with the sun, but chief among them were Horus