I don't want to be an ass and tell this guy what he believes for him, but if someone claims only that god 'exists', without elaborating on any particular details about what sort of entity they are, it leads me to believe that they want to avoid the label atheist/agnostic for optics, but otherwise have an agnostic viewpoint (especially if they are willing to go so far as to say it doesn't matter if the god is 'real').
The claim about God being similar to morality or other things that become "real" through shared perception to me does not have any philosophical rigour. God is a different category of thing from morality or whatever other cultural phenomenon you want to compare it to.
You can 'believe' in morality or cultural phenomenon without having to think anything is real. The only thing that makes cultural phenomena real IS the fact that it is perceived to exist in our heads.
God is totally different. If you don't believe your God created the universe and/or life, the God you believe in is not a God by any sensible definition of the word.
If you find it equally possible that life in the universe could have just as easily arisen though purely mechanistic means as described by the laws of physics, then you do not believe in a God (unless you want to argue that they designed the laws of physics to eventually create life naturally).
Whether it's life itself being designed, or the laws of physics being designed to facilitate life, I think its fair to say you must believe the universe was intentionally crafted in some way to facilitate life in order for a god to exist.
This event, of the universe and/or life being conceived and instantiated refers to an actual event in astronomical history. It refers to a category of thing that's more real than the cultural phenomenon this guy compares it to.
You completely ignored everything I said. You have no faith, you believe in nothing, other than adhering to labels that are favourable to your social circumstances and avoiding labels that aren't.