>>To say your god is the only god is the height of arrogance and stupidity, IMO.
The difference is we are not saying "our" god is the only god. We are saying there is only one god, commonly referred to as "God". If He is omnipotent - there can only be one omnipotence, one omniscience, etc. so the idea of many gods doesn't hold. Our understandings of this one God may differ.
Since this God is infinite and intelligent far beyond us, it's reasonable to assume He gave us special revelation (scripture). We can assume there will be one true revelation and many false ones. We can peruse the books that claim to be the special revelation and quickly eliminate the false ones through a simple test. We then diligently study the one true revelation so we can know God as He has revealed Himself. We then live according to His purpose and find love, joy, peace, patience, understanding, wisdom, gentleness, etc.
It's really quite simple. If you think about it, it should be simple so that all people can seek God. It should be "right at hand" and it is.