If I'm reading you properly, being a "realist" in this case apparently means you are "compelled" to conclude that there is no God, because you know reality, and He's not part of it.
There's an underlying assumption in that position, which is that you have an a priori -- not to mention innate -- understanding of what consitutes "reality." Think about that for a moment. Are you sure you can support that position?
the problem with that, is what you consider real, is what you perceive in 4 dimensions. Modern science confirms what was clear from studying the bible, that there are more than 4. A rabbi in the 12th century said he believed there were 10 based on his study of the first verse of Genesis, 4 that we could discern directly and six that we could not.
Also the God of the bible said that he confirmed his word by telling the end before the beginning, which if true could only be done by someone altogether outside of the time domain. Just food for thought.