There are many gods and many lords.. Even in ancient bible times, people worship many idols which they refer to as their god.. But in revelation chapter 4: 11, the bible made us to understand that Jehovah rightly deserved the glory,honour ,and power because he created all things and because of him, all other things came into existence.. Which other god has done any creating apart from the one true God Jehovah?? So yes. We have only one God, whose name is Jehovah.. A name that no other gods nor humans can bear..
People believed that there is one upper most supreme being that owns and controls the whole universe, who no one can question is actions and dealings on anything in the whole universe/world . Thus they term him to be the Almighty God. All religion accept and confirm that through their holy books or incantation.