Christians maintain that God is a real thing. They maintain is it observable to atheists if the atheist chooses to acknowledge its existence. Since one cannot choose to believe something to exist which is contrary to what they do believe, it suggests Christians are actually Pantheists and “God” is just a term used in lieu of a real thing or a set of real things.
No, it just implies that Theists are wrong about their assumptions and their claims.
Perhaps it’s nothing more nor less than the instinct to survive and to thrive. That instinct has evolved into something more meaningful and on a higher plane of existence. Just a theory…but perhaps it’s someone else’s too. 
Instincts do not know everything. An instinct doesn’t know how many water buffalo there are in Africa.
Instincts can’t do anything. An instinct can’t turn a spark plug into a waterfall the size of Niagara Falls.
Instincts don’t love everyone. Instincts probably don’t love every person who lives in Yemen.
Yet Christians say God knows everything, can do anything and loves everyone. Why would they so confidently state this if it is so egregiously wrong?
But Christians claim to have a personal relationship with God … and that you can too if you just believe ; that without believing you can’t know the reality of a personal relationship with the God of all.
So Hobbes, all you have to do to realize the existence of God is believe ; it’s like a switch that turns it all on.
Please explain how one goes about choosing to believe something exists when such existence of it is contrary to your intellect.
E.g. try to believe it is 100 degrees F and snowing in the middle of the Sahara Desert right now.
And where did I say that they “know” or have to know everything? But they do have a particular kind of knowledge which acts upon them and would in fact tell them “hey, it’s time to go…run for your life”, when they see those buffalo coming at them.
Sure they can do some things. They can turn us away from danger if we listen to them and if we so wish to be turned away from danger. They might also keep someone from pushing that final button which will annihilate us all, if there be such a button.
But if we pay attention, our instincts may tell us who it is safe to love and who not to love.
Because so much of the nature of belief is simply illusion…the desire for something no matter how ridiculous it may be or how unfounded we intuit it to be. … and because we do not always have the capacity to doubt our beliefs. It is not only a christian who has the monopoly on this. We all do at times.
And besides, what would be the purpose for many to have a god or to believe in one if that god was not omnicient, omnipotent and an all-embracing loving one? We create out of need.
You can choose to pretend to believe something, assess the consequences of that “belief”, and depending on the results your beliefs may change in some way. You divorce non-disparate things, like imagination and reality. We create our realities, even if sometimes our bubbles can burst. Belief isn’t merely passive, it is also active. We are experimenters.