Do theists agree that knowledge of God is natural knowledge? What do atheists think of this concept? Does it seem silly?
I don't accept that there is any knowledge about gods, innate or acquired. By knowledge, I mean beliefs derived empirically and considered to be true because they are demonstrably able to accurately map some aspect of experience in a way that helps one anticipate outcomes and accomplish his goals. Nothing called knowledge of God can do that. Things said about gods cannot be demonstrated, nor can such ideas be used in any way except as psychological support for those who feel more comfortable holding such a belief. Even that is not knowledge of God.
God becomes clear when we detach ourselves from our ego; this is the process of discovering God.
I don't know what people mean when they refer to detaching themselves from their egos. We are our egos. Ego mean I, or self. The ego is the observer, the subject apprehending the objects comprising the theater of consciousness - external and bodily sensations, thoughts, feelings, desires, etc..
Maybe they mean be more humble, or less interested in one's own desires, or something else.
But I find it interesting to consider fragmenting the ego, separating out the piece that Freud called superego, and projecting it onto the universe as if it were something other than self, something more noble than what was left behind. I've long thought that what others intuit as God is really self misunderstood.
Here's the part that might annoy some theists, because they see it as blasphemous and arrogant, but how about we reintegrate that aspect of the self and realize that the gods we perceive are the best parts of ourselves. The theist will often call this playing God, and disapprove, but it can be quite uplifting. I recall several times when, while living in rural Missouri (USA), mine would be would be the only vehicle visible in either direction on a country road that a turtle was slowly crossing. I would always pull over and carry the creature to its destination before somebody ran it over, deliberately or otherwise. I was an atheist, and had no concept of being watched from above or being rewarded by a deity. I assumed that nobody saw me, or would know what I had done.
But I felt a frisson pass over me when I did such things. Here I was doing for this creature what no god was doing. I was fulfilling that role, and I felt godlike - not in an egotistical way, not in the sense that I was a god, but in the sense that I was the closest thing to one I was aware actually existed. I had taken responsibility for a corner of our universe, and the feeling of satisfaction was spiritual.
Let's go back to Freud's idea of the self - a higher self called the superego, an observing self called the ego, and a base self called the id: "According to Freud psychoanalytic theory, the id is the primitive and instinctual part of the mind that contains sexual and aggressive drives and hidden memories, the super-ego operates as a moral conscience, and the ego is the realistic part that mediates between the desires of the id and the super-ego." This has been anthropomorphized as three characters:
To me, these are all the self. What some people seem to have done is to separate out the superego, project it onto the universe, and see it as God, leaving behind only a wretched, sinful self. This would result in people seeing themselves as worms, unworthy, base flesh, inherently sinful, seeking the missing piece as if it were somewhere out there and more noble than what is left in here. What people describe as the endless search to get closer to God is merely themselves trying to patch themselves back together after being convinced that part of it wasn't themselves.
But if one reattaches his higher self to the rest, and learn to tame the beast, then gods disappear and that person can assume the role of god in his own life. As I said, I know how this offends theists, but there it is nevertheless.