Not directly but there are ways of observing them indirectly via their effects.
Well, we can also observe the effect of God, namely, the creation. This is the basis for
natural theology. The bottom line is that your subjective awareness cannot be objectively observe. So, I have no scientifically valid way to determine whether you are presently experiencing it. But I think it is rational for me to infer that you are based on outward things that I can observe. Inferring the existence of God is just as rational, the atheistic demand for scientific validation notwithstanding.
By the way, on the materialist view, consciousness (subjective awareness) is causally inert. Free will (which materialism precludes) is the only possible role that consciousness can play. In fact, belief in any kind of intelligent agency is a supernatural belief because
methodological naturalism (a.k.a. science and the basis for
metaphysical naturalism) cannot detect intelligence (divine, human, or otherwise).
On what basis are you declaring God to be subjective though?
The basis is rational. Reason tells me that I am seeking the highest or supreme good (which presupposes a
telos and therefore a conscious intelligence).
The rest of your post amounts to nothing more than rambling about nothing.