UFOs and Religion
The gods and flying vehicles are a common theme in most of the major and minor religious writings.  Africa, Asia, Europe, the Americas, Australia and almost every culture on Earth have religious or traditional beliefs with flying entities at the center.
Sumerian
In Ancient Sumer, clay tablets describe visits of the gods. The gods fly in vehicles called Shems, or Mu, which are described as being tall rocket-like "rocks" from which fire flies. The visiting gods stay at temples, built by humans under the instructions of the gods, and are waited on. Certainly, the detailed descriptions of everything from who shakes hands with the gods first, to what food is served, and how the gods are carried back to their Shems imply that the Sumerians weren't just expecting spiritual visitors, but physical beings from the sky.
Egyptian
The Egyptian Book of the Dead "Behold, oh ye shining ones, ye men and gods...“  "I speak with the followers of the gods. I speak with the disk. I speak with the shining ones."  The Egyptian name is "Benu" which means  "the Ascending One".  Egyptian King Pepi ascends: “As an imperishable star; Flies who flies! He flies away from you, O men! He is no longer upon earth; he is in the sky! He rushes at the sky like a heron.  He has kissed the sky like a falcon.  He has leapt skyward like a grasshopper.”  Ancient Egyptian legends tell of "Tep Zepi" or the First Time. This is described as an age when "sky gods" came down to Earth and raised the land from mud and water. They supposedly flew through the air in flying "boats" and brought laws and wisdom to man through a royal line of pharaohs.