Christianity professes to be a monotheistic religion, and most Christians consider Jesus of Nazareth to be not only divine but one and the same as God himself. And Jesus most certainly walked among human beings during his lifetime.
Islam considers Mohammed, who also lived on earth, to be the prophet of Allah, but Islam is more ambivalent about whether Mohammed was himself divine.
Judaism generally marks a clear separation between the human and divine worlds, but even Judaism has many stories of humans interacting with God on earth (Moses receiving the Ten Commandments, for instance).
So one answer to your question might be that the world's largest monotheistic religions (Judaism, Christianity, and Islam) do have examples of gods coexisting on earth with humans, but that these examples are rare and sources of great theological controversy.
