So? Your God is Jesus and he is depicted on crucifixes and stain glass. An image is not meant to be an
exact representation of a God. It's only shallow theology that has this. So as long as your God, Jesus, is being depicted on stained glass and can yet be described as 'invisible', then so can Amun.
Amun is also literally described as a transcendent Creator God who creates the other Gods. You can't really ask much more than that, I'm afraid.
In the Old Kingdom record, Amun was conceptualized as a hidden, primordial deity, a great one, who existed before creation came into being and who was associated with the throne of Egypt.
Assmann's preliminary summary of the motifs and characteristics by which the post-Amarna, Amun-Re theology may be recognized most clearly has following points :
"1. the emphasis on the oneness and hiddenness of the god ;
2. the predication of the god as 'i.ba' in connection with the concept of hiddenness ;
3. the formula of the 'one who makes himself into millions', with all its variants ;
4. the concept of the god dwelling in the world as 'ba', image and body, who has created the world as earth, heaven and underworld for these three constituent elements of his self ;
5. the theory of the 'life-giving elements', i.e. the concept that god sustains and gives life to the world not only by, but also as light, air and water ;
6. the idea of all-prevasiveness in the form of air, as is expressed in the formula (Jmn) mnw m jht nbt [(Amun) enduring in all things] ;
7. the role of this god as god of time and fate in connection with (num 8)
8. his personal aspect as 'ethical authority'." - Assmann, 1995, p.133
Hence, oneness characterized all possible transformations of Amun-Re :
- before creation : Amun (here "Re" should not be added, because there was no Sun god in existence yet) is a primordial god, "existing" before existence (like Atum in Nun) ;
- during creation as sole creator : Amun-Re is the creator, transforming the primeval word into the cosmos (as Atum hatched out the primordia egg by himself) ;
- after creation as pantheon : Amun-Re is "hidden" behind all other deities who are his images, forms, manifestations, transformations and names.
The distinction between :
- an absolute unity, or ultimate, primordial cause, which remains identical with itself and unopposed to anything (but out of which "sui generis" creation unfolds) and
- a (self-created) creator, the first cause or first number, is explicit in the difference between pre-creation (with its Ogdoadic inertness rooted in Nun) and the "first time" of Atum-Re, who creates himself out of himself and all the rest of existence out of his own body. Atum splits as soon as he emerges, and so his creativity is always tangential (mythical, fugal), for it was the Ennead -sprang out of him-, which ruled the affairs of the world. Hence, the first cause is Re, the final manifestation of Atum, self-creating himself in eternity-in-everlastingness.
Hence, the oneness of Amun-Re covers pre-creation, the creator and creation. It is an all-encompassing oneness, also to be found in the
Memphite theology of the period.
ANCIENT EGYPT : Amun and the One, Great & Hidden (sofiatopia.org)