Dear Wilhelmus,
Too often when we speak of God we are understood through the misconceptions of others. As these are attributed to us. I try to avoid such discussions all together. I am perfectly comfortable with the notion that God exists or God does not exist! Or even God may in the future exist. Or had existed at one time.
But I am convinced (and have good reasons to be convinced as per my essay) any description of 'what is' the Universe is metaphysical. Whether mathematical or not! And any such metaphysical description will ultimately fail. Just as it has in the past. And it will fail because the Metaphysics stretches the limits of the sensible. And so it is no longer believed. I believe we are near that point now with Modern Physics.
But in my essay I also argue Physics can be based on mathematical 'truisms' applied to measurements. Though we cannot know 'what is', we certainly know our measurements of 'what is'. And though there is no logical basis that the Universe follows mathematical 'models', there is logical certainty applying mathematical 'truisms' to measurements.
Thank you for your good wishes ...
Constantinos