A continual part of Steve Quayle's research is about UFOs and Giants.
www.stevequayle.com/giants.of.Earth/pics/giants.html
www.greatdreams.com/reptlan/giants.htm
www.reptoids.com/Vault/gc_ArizonaGazette5April1909.htm
www.bibliotecapleyades.net/sumer_anunnaki/reptiles/reptiles.htm#menu
It seems that some religions have been set up to focus the human mind into a particular set pattern. That positive life & consciousness only exists on earth. Perhaps someone decided that most people wouldn't be able to discern if some off world life was actually quite benevolent, amidst all the malevolent & mysterious ones out there. Various ufos could range from being robotic spaceships & time crafts, to vehicles that feature a wide spectrum of physical beings & other forms of consciousness. Its very difficult for many to seriously digest all the possibilities.
http://www.biblebelievers.org.au/giants.htm