The great savant contemplated this for several spans before replying in the negative. "You are mistaken. No reality can be modeled completely by a calculating engine that is contained within and partaking of the same reality. God did not use a computer to create the world. He used mathematics."
The student pondered this wisdom for a long time, then persisted in his argument. "That may have been the case when it came to envisioning and creating the world, Master --- and to foreseeing future consequences in revealed destiny --- but what of maintenance? The cosmos is a vast, intricate network of decisions. Choices are made every femtosecond, and living beings win accordingly, or else lose. "How can the Creator's assistants carry out these myriad local branchings, unless they use computer models?"
But once again, the great savant turned his gaze away in rebuke. "It is Ifni, the chief deputy, who decides such things. But she has no need for elaborate tools for deciding local events. In the Creator's name she runs the world by using dice."
--- David Brin, "Infinity's shore"