Perfect being theology holds that God is, well, a perfect being. However, the meaning of "perfect" in this context is ambiguous. Usually it is associated with classical theism, which holds that God is omnipotent, omniscient, perfectly good, and so forth. But these concepts are also heavily debated.
While it would be nice if we could avail ourselves of the testimony of some special revelation, like an inspired written text, I personally do not think there are any plausible candidates for an authentic special revelation. I used to treat the Bible as a divine revelation, but I came to reject that view (and still reject it) for reasons that I've discussed elsewhere. I've never been drawn to the Quran or any other religious text, and I have some reasons for doubting that God would communicate to us through written texts anyway (although I freely admit that I could be wrong). As a result, I am limited to what I can learn from philosophy and natural theology as well as from personal experience.