Why do you not believe in God?

[Skepsis]

So suppose knowledge of God was properly basic, perhaps some people have it and others lose trust in it, because it's not able to be tested? But in this case, it surely is not wrong to trust it.

Perhaps "spirituality" is the form of constantly testing our knowledge of God and why people feel the need to practice a religion?

So, there's this little thing humans have that we develop an aversion to at an early age... it's called FEAR.
You see, fear is something that is invoked when an individual feels a situation is likely to end in his/her detriment, especially in the case of physical harm, pain, or long-term loss of some kind or another.
Fear has always been a basic, ingrained thought pattern necessary for survival (or increased survival chances). The reason religion was developed was in large part to allow for an escape from the fear of death, loss of loved ones, and the ability to never fear anything again after a certain event- death. That way, God can avoid the axe of logic. At least for the gullible.
When you say that religion, or "spirituality" in your case, is a basic belief, you are asserting that a human with no contact in any sense with any other person would have knowledge of God.
Prove it.
Your full of shit if you really think that. You are equating my comments about logic having been tested (in a sense) by nature to the idea that people naturally have a belief, or at least an understanding, of a God or something of the sort.
Nobody intuits God. People might intuitively develop an imaginary friend, but it is to allieviate another human faculty called "loneliness".
Beliefs that conflict with, contradict, or ignore logic nearly always serve a purpose to the believer. Most of the time these beliefs are ingraned, but they can be developed solely by the adherent, in which case the believer likely just wishes the proposition to be true for some reason.