Neb Kepheru Ra
Egypt did not worship the sun. That's just foolishness, intended to deprecate them as spiritual savages. Ahkenaten and others held that as the sun is the source of all that gives us life on earth, it is the perfect symbol for the greater light that gives existence to all the universe, without which... or more accurately, without whom... there is no universe at all. That infinite, eternal, and pre-primal consciousness is the One whom Egypt called Aten, the Hebrews knew as the unknowable YHWH, the Muslims as Allah, Scientologists as Theta, and others simply as God the unnamed.
The cartouche is Tut's Name Of Horus. Roughly speaking, that means where Tutankhamun was the name of Pharoah's body, Nebkepherura was the name of his spirit. It can be translated "vessel of the endless resurrections of God" or "sunrise from a basket of shit" or in a word, "The Resurrected." To understand it is to know why Kepher the dung beetle is held sacred, and why she is the glyph for beginning and renewing. Without Kepher to turn the cowshit, there would be no Egypt.
Seeing thereby our place in the eternal shit cycle, we can come to realize that as the sun is always shining, and night is but an illusion, the life is not lost when the body passes, but like the sun, also shines eternal. Osiris was dead, murdered by his jealous brother Set and ressurected by his loving sister Isis, and he knew it. Thus enlightened, he became Lord Of The Dead, and that is why his glyph is the eye. He is the one who sees through the veil, and who is there to greet and judge you when you find yourself without the ka, without an avatar, yet still conscious. Life without end does not mean you never die. It means you always die.
"As you were in the beginning, you are now, and always shall be."