Is God a spiritual guide to Jaromir in this story? Well, maybe. Jaromir does pray to God, after all, and you'll notice that he doesn't question God's existence. Instead, he questions his own existence, and God's presence is taken for granted. What is up for debate is whether Jaromir himself is merely one of God's "repetitions or errata" (6).
Jaromir does have a couple of strangely prophetic dreams. In the second one, he hears a voice. A divine voice? Could be.
So is God a character in this story? Well, that's definitely one way of explaining Jaromir's "secret miracle." Then again, no one else can actually see this secret miracle: Jaromir is the only one who gets to experience it. So is God a figment of Jaromir's imagination? Is Jaromir a figment of God's imagination? Ah, the ambiguity.