This is not a god (abrahamic) specific question but it can incoporate all gods under the spirit-ual sense. I dont know what a deity is, so any god deity (i.e. being) or not (i.e. panthentheism) is fine.
What makes something real?
A lot of us have spiritual and supernatural and whatever-you-want-to-call it experiences that you know for yourself and/or you know for everyone it is true whether we can explain it or not. Unfortunately, no one does, if not at least in their own words.
So, what formula do you consider your experiences real regardless if others believe you or not?
Some experiences are not specific to religion. Say mystics
Some are specific to culture. Say hindu.
Some are specific to whats written. Say jewish
Some are specfic to ones own criteria of truth. (FITB)
Some.....
Whether it all applies or you like to say "not me" just to post is besides the point.
If it is not tangible and you cannot explain it as a source of your psych nor a reflection of external sources (unexplained convincing event? Something that convinced you there is more out there. Whatever)...
It does not matter if it is real or fact to us.
How is it real to you?
Not just testimony. Explain your logic. If you dont like talking about it, make up one thats simular to your understanding of how you know something is real without needing it to be tangible or explained by universal criteria of whats fact)
For me something is real when it is shown to be consistent with what fits reality, or what is. Hard to explain, so an illustration is fitting.
Say someone felt heat, when they put their hand in a particular space. The closer they moved toward that space, the more intense the heat. So they run a small test. They throw paper into the general area, and the paper was singed, or even disintegrated.
I conclude that whatever is there is real - it exists, even though I can't visibly detect it.
It's like, with the force of gravity, magnetism, etc.
So for me, it comes down to having to use our senses to determine what is real.
Another example...
If someone told me something a million times, and each time it check out, I trust that the knowledge that person has given, of the particular is real, so even though it was not known to me, before I knew... it was real - if that makes sense.