I follow a spiritual philosophy which dictates that the Divine is immanent in every aspect of creation and transcends creation, possessing no limit. Using reason, if one equates God with the sum of everything that exists, both material and immaterial, the nature and existence of God can then no longer be called into question.
We have both commented on this, in full agreement. As per Advaita, God/the Self/Pure Consciousness/Atma-Brahman/the Absolute–Supreme Being is the only reality, “One without a second”. This, however, is not pantheism but panentheism. God transcends his creation (you said it yourself) and is greater than it; thus God and his creation are not identical, which is the view of pantheism.
“the thinker exists because the thinker is in fact conscious”
Yes. Although a personal relationship obtains between God and ‘individual’ man, ultimately, essentially ‘Man’ is ‘God’, the self is not other than the Self, Pure Consciousness. (You must have read about the deiform nature of man, a doctrine of St. Ireneus of Lyons). But as long as an individual feels him/herself separate from that one reality, the path of devotion (or that of ‘works’, karma yoga) is appropriate for that person. Well, all this is perhaps too much, and for many people it would be sacrilegious, but somehow I think that you will resonate with it in some measure.