Clarifying the Existence of God

I have difficulty understanding why, on the one hand, God guides me in religious (and probably moral) values, and on the other hand, He does not make it clear to me that He exists and that He expects me to uphold them.
 
What is the advantage of not being 100% certain that God exists? And that maybe I don't really have a commandment?
 
Doesn't this call into question the very claim that God does indeed command?
That is, the question can be formulated as follows: If God cared what you would observe and what you would not, He would at least make it clear to you.