There are many things that something would have to be in order to be properly called “God”. For instance, it would have to be all-powerful, because a part of what “God” means is “all-powerful”. To call something that isn’t all-powerful God would be like calling a shape that doesn’t have three sides a triangle; to anyone who understands the words involved it just wouldn’t make sense. Another part of what “God” mean is “perfect”; something can’t properly be called God unless it is perfect. This is the key idea behind the ontological argument.