Where does it say that one has to understand God in order to be able to worship Him?
Hebrews 11:6
But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.
You do not have faith in a vague blob, and abstract principle. God showed you what He was like (at least a glimpse of Himself) in Scripture. If you reject that, you worship a different God altogether.