If there is a God .. is there only 1?

I know that in the bible God says:'Thou shalt have no other God but me'Although probably not in English , but does that
mean that he is just one of many Gods, but does not
want his followers worshipping any others ... or
is there some qualification that makes it clear
that (biblically speaking) He is the only God in existence?

Based upon what?A quick re-read of Genesis and Exodus should point to
the opposite.If the Jewish people were convinced of a single God
always, why did Abraham and Moses have to go to such lengths
to show their respective people's the error of their polytheistic
ways?

I'd have to question the omnipotent nature of the
biblical God.He floods the earth when he could have 'disappeared'
mankind.He has to rain plagues on Egypt to convince Pharoah to
let the Isrealites go ... when he could have just made Pharoah
do it, ot just zap them to their own land.He couldn't even provide the Isrealites with their own lands
they had to take Canaan by force.Hardly signs of omnipotence.

Doesn't the 'sense' of the Bible, though, suggest that
in the beginning the authors believed in the existence
of a number of gods, and that towards the end of OT
they believed in only one.Doesn't that suggest that the bible is not the inerrant
word of god, but the errant word of man.The message may well be valid ... that doesn't mean that every
word is the literal truth.