Unless there is a reasonable answer to this question, one can only assume that God is not part of the measurable world, and therefore not part of reality and therefore not real.
If you ascribe to ID then the assumption is God is detected in three ways:
1. Ontologically 2. Teleologically 3. Spiritually
The ontological argument, stripped down, essentially means that because the concept of God is so pervasive it lends credence that in fact God may exist.
The teleological argument states that design and order could not randomly come about.
The spiritual argument is that God must be experienced personally. That "meeting God" is subjective to the individual experience.
In the final analysis there is a rebuttal for each.
In my estimation, God, by the very supernature of its alleged being, cannot be verified or falsified.
Each person has to make their own deduction. What can be done, to some degree, is taking specific arguments about God and testing it. It has to be specific because the concepts of God are not universal.
However, if the supposition is that the bible, for instance, is the infallible Word of God, one can test many of these claims by juxtaposing it with measurable data and physical evidence.
"Men never do evil so completely and cheerfully as when they do it from mistaken conviction." – Blaise Pascal